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Die Anzahl von mit Hilfe der Internettechnologie im Web zur Verfügung gestellten offenen API (Open APIs) zeigt ein exponentielles Wachstum. Auf der Grundlage kompositorisch zusammengesetzter APIs entstehen innovative Lösungen, die sich zunehmend als Treiber der Digitalisierung positionieren. Vor diesem Hintergrund gilt es, Open APIs aus der Perspektive der fachlichen Nutzung zu gestalten, so dass diese in möglichst vielfältigen Anwendungsszenarien stabil und nachhaltig verwendet werden können. In diesem Zusammenhang wird auch von einer „API first“-Strategie gesprochen. Die erste Session des Workshops widmet sich dieser Themenstellung, wobei u.a. auf Fragen der API-Gestaltung mit Hilfe einer OpenAPI bzw. Swagger Spezifikation eingegangen wird. Mit Aspekten des entwicklungsseitig und betrieblich benötigten API-Managements beschäftigt sich dann die zweite Session. Dabei soll sowohl auf Aspekte der Identifizierung und Authentifizierung konkreter API-Zugriffe als auch auf die Themenstellung einer DevOps-orientierten API-Bereitstellung eingegangen werden. Innovative Techniken, welche im Diskurs einer kompositorischen Softwareentwicklung verwendet werden können, stehen im Mittelpunkt der letzten Session. Dabei geht es zunächst um die durch Facebook propagierte Abfragesprache GraphQL, welche die Einbindung von httpbasierten APIs vereinfachen soll. Ein weiterer Beitrag beschreibt die Entwicklung einer mobil einsetzbaren Serviceapplikation, die umfangreichen Gebrauch von Open APIs macht. Dabei wird auf lokal installierte Entwicklungsumgebungen weitgehend verzichtet, d.h. auch diese findet Cloud-basiert statt. Der thematische Hintergrund dieses Workshops entstammt dem im letzten Jahr in Berlin durchgeführten ESAPI-Workshop (speziell dem World Café). Die Ergebnisse der dort diskutierten Fragen sind im letzten Beitrag dokumentiert.
Since its introduction in 2014, the face morphing forgery (FMF) attack has received significant attention from the biometric and media forensic research communities. The attack aims at creating artificially weakened templates which can be successfully matched against multiple persons. If successful, the attack has an immense impact on many biometric authentication scenarios including the application of electronic machine-readable travel document (eMRTD) at automated border control gates. We extend the StirTrace framework for benchmarking FMF attacks by adding five issues: a novel three-fold definition for the quality of morphed images, a novel FMF realisation (combined morphing), a post-processing operation to simulate the digital image format used in eMRTD (passport scaling 15 kB), an automated face recognition system (VGG face descriptor) as additional means for biometric quality assessment and two feature spaces for FMF detection (keypoint features and fusion of keypoint and Benford features) as additional means for forensic quality assessment. We show that the impact of StirTrace post-processing operations on the biometric quality of morphed face images is negligible except for two noise operators and passport scaling 15 kB, the impact on the forensic quality depends on the type of post-processing, and the new FMF realisation outperforms the previously considered ones.
Reducing the False Alarm Rate for Face Morph Detection by a Morph Pipeline Footprint Detector
(2018)
This paper introduces an approach to automatic generation of visually faultless facial morphs along with a proposal on how such morphs can be automatically detected. It is endeavored that the created morphs cannot be recognized as such with the naked eye and a reference automatic face recognition (AFR) system produces high similarity scores while matching a morph against faces of persons who participated in morphing. Automatic generation of morphs allows for creating abundant experimental data, which is essential (i) for evaluating the performance of AFR systems to reject morphs and (ii) for training forensic systems to detect morphs. Our first experiment shows that human performance to distinguish between morphed and genuine face images is close to random guessing. In our second experiment, the reference AFR system has verified 11.78% of morphs against any of genuine images at the decision threshold of 1% false acceptance rate. These results indicate that facial morphing is a serious threat to access control systems aided by AFR and establish the need for morph detection approaches. Our third experiment shows that the distribution of Benford features extracted from quantized DCT coefficients of JPEG-compressed morphs is substantially different from that of genuine images enabling the automatic detection of morphs.
We analyze StirTrace towards benchmarking face morphing forgeries and extending it by additional scaling functions for the face biometrics scenario. We benchmark a Benford's law based multi-compression-anomaly detection approach and acceptance rates of morphs for a face matcher to determine the impact of the processing on the quality of the forgeries. We use 2 different approaches for automatically creating 3940 images of morphed faces. Based on this data set, 86614 images are created using StirTrace. A manual selection of 183 high quality morphs is used to derive tendencies based on the subjective forgery quality. Our results show that the anomaly detection seems to be able to detect anomalies in the morphing regions, the multi-compression-anomaly detection performance after the processing can be differentiated into good (e.g. cropping), partially critical (e.g. rotation) and critical results (e.g. additive noise). The influence of the processing on the biometric matcher is marginal.
In 2014 a novel identity theft scheme targeting specific application scenarios in face biometrics was introduced. In this scheme, a so called face morph melts two or more face images of different persons into one image, which is visually similar to multiple real world persons. Based on this non authentic image, it is possible to apply for an image based identity document to be issued by a corresponding authority. Thus, multiple persons can use such a document to pass image based person verification scenarios with a single document containing an artificially weakened template. Currently there is no reliable existing security mechanism to detect this attack.
The paper presents an observation and evaluation of the recovery process. Seven weeks after the fracture of the fibula and six weeks after surgery the measurement of the gait of the subject has been started. Inertial measurement units applied above both ankles are used to acquire kinematical data and three surface EMG at each leg to get information about the activity of three muscles. The intensity of the weekly tests has been increased in dependence on the healing progress. Both scenarios-walking on the floor and on the treadmill-were included in the experiments to obtain comparable data sets. Beside of the investigation of the healing process the paper is focused on symmetry/asymmetry properties of the gait. The results indicate that asymmetry is not only an essential property of pathologic gait but it is present in normal gait too, especially if short distances are evaluated. They may be caused by the influence of a dominant/injured leg, of the first/last steps, the natural variance of the gait or the daily fitness of the subject. Asymmetry is obviously in the contribution of both legs to a stride (step length, strike and lift angle, stand and swing phase).
Unsere Welt verändert sich in unterschiedlichen Tempi und Verwerfungstiefen. Dies ist das einzig Verlässliche für Wirtschaft und Gesellschaft.
Zum einen zählt die kreative Zerstörung zum ‚Markenkern‘ marktwirtschaftlicher Systeme. Die Wirtschaftsakteure stehen dadurch an ihrem jeweiligen Standort unter einer Art (produktivem) Dauerstress. Es gibt Gewinner und Verlierer, weil Wettbewerber unterschiedlich erfolgreich kostensenkende Rationalisierungen, technischen Fortschritt und die Erschließung neuer (globaler) Märkte realisieren. Der damit einhergehende Strukturwandel gilt als wirtschaftssystemischer Normalzustand.
Zum anderen gibt es Krisen. Und auch ‚unter Schock‘ (re-)agieren Akteure ungleich, wie die Corona-Pandemie oder abrupte Veränderungen durch die Finanzkrise zeigen. Einige Akteure und Standorte bleiben mit ihrem jeweiligen Profil und Potenzial (weiterhin) produktiv widerstandsfähig. Für andere verschärfen sich der wirtschaftliche Niedergang und dessen Folgen für die Arbeitsmärkte und Lebensqualität der Betroffenen.
Regionale Wirtschaftsförderung unterstützt, dass sich die Wirtschaftsstrukturen an einem Standort überlebensfähig ausrichten. Doch kann sie auch beim Umgang mit Krisen einen Mehrwert erzielen und zählt dies überhaupt zu ihrem Regelauftrag? Und welche Rolle spielt die Digitalisierung? Der Beitrag stellt den sachlogischen Zusammenhang zwischen diesen Teilfragen her und ordnet neuere Ansätze ein. Zudem werden Ansatzstellen aufgezeigt, um die regionale Wirtschaftsförderung praxisorientiert weiterzuentwickeln. ‚Electronic Government‘ (E-Government) beschreibt dabei den Einsatz von Informationstechnik, Telekommunikation und Medien (ITKM) im öffentlichen Sektor, während ‚Electronic Governance‘ (E-Governance) hybride oder private Akteure miteinbezieht.
Der Beitrag ist wie folgt strukturiert: Zunächst werden Schlüsselbegriffe wie Strukturpolitik und Resilienz geklärt und mit den Kontextfaktoren verknüpft, welche die Steuerungslogik von Wirtschaftsförderung bestimmen. Danach wird diskutiert, inwiefern die Wirtschaftsförderung E-Government und E-Governance nutzen kann, um Resilienz zu stärken und möglichst transformativ wirken zu können.
The public sector faces several challenges, such as a number of external and internal demands for change, citizens' dissatisfaction and frustration with public sector organizations, that need to be addressed. An alternative to the traditional top-down development of public services is co-creation of public services. Co-creation promotes collaboration between stakeholders with the aim to create better public services and achieve public values. At the same time, data analytics has been fuelled by the availability of immense amounts of textual data. Whilst both co-creation and TA have been used in the private sector, we study existing works on the application of Text Analytics (TA) techniques on text data to support public service co-creation. We systematically review 75 of the 979 papers that focus directly or indirectly on the application of TA in the context of public service development. In our review, we analyze the TA techniques, the public service they support, public value outcomes, and the co-creation phase they are used in. Our findings indicate that the TA implementation for co-creation is still in its early stages and thus still limited. Our research framework promotes the concept and stimulates the strengthening of the role of Text Analytics techniques to support public sector organisations and their use of co-creation process. From policy-makers' and public administration managers' standpoints, our findings and the proposed research framework can be used as a guideline in developing a strategy for the designing co-created and user-centred public services.
Limitierende Faktoren
(2023)
Wie bei allen Risiken gibt es auch bei Compliance-Risiken kein Null-Risiko. Man wird in der Praxis noch nicht einmal in die unmittelbare Nähe einer Null kommen. Ein Null-Compliance-Risiko ist auch deshalb nicht erreichbar, weil sich ständig neue Risikofelder auftun. So beispielsweise durch Änderung von Geschäftsmodellen oder Vertriebswegen oder durch neue rechtliche Rahmenbedingen.
Disclinations or disclination clusters in smectic C freely suspended films with topological charges larger than one are unstable. They disintegrate, preferably in a spatially symmetric fashion, into single defects with individual charges of +1, which is the smallest positive topological charge allowed in polar vector fields. While the opposite process of defect annihilation is well-defined by the initial defect positions, disintegration starts from a singular state and the following scenario including the emerging regular defect patterns must be selected by specific mechanisms. We analyze experimental data and compare them with a simple model where the defect clusters adiabatically pass quasi-equilibrium solutions in one-constant approximation. It is found that the defects arrange in geometrical patterns that correspond very closely to superimposed singular defect solutions, without additional director distortions. The patterns expand by affine transformations where all distances between individual defects scale with the same time-dependent scaling factor proportional to the square-root of time.
We present a method for the arbitrage-free interpolation of plain-vanilla option prices and implied volatilities, which is based on a system of integral equations that relates terminal density and option prices. Using a discretization of the terminal density, we write these integral equations as a system of linear equations. We show that the kernel matrix of this system is, in general, ill-conditioned, so that it cannot be solved for the discretized density using a naive approach. Instead, we construct a sparse model for the kernel matrix using singular value decomposition (SVD), which allows us not only to systematically improve the condition number of the kernel matrix, but also determines the computational effort and accuracy of our method. In order to allow for the treatment of realistic inputs that may contain arbitrage, we reformulate the system of linear equations as an optimization problem, in which the SVD-transformed density minimizes the error between the input prices and the arbitrage-free prices generated by our method. To further stabilize the method in the presence of noisy input prices or arbitrage, we apply an 𝐿1-regularization to the SVD-transformed density. Our approach, which is inspired by recent progress in theoretical physics, offers a flexible and efficient framework for the arbitrage-free interpolation of plain-vanilla option prices and implied volatilities, without the need to explicitly specify a stochastic process, expansion basis functions or any other kind of model. We demonstrate the capabilities of our method in a number of artificial and realistic test cases.
The Patellostabilometer: A New Device for Quantification of Mediolateral Patella Displacement
(2023)
Mediolateral patella displacement is of interest for diagnostics and clinically relevant
research questions. Apart from manual testing, no standardized method is currently available. Proper
quantification of patella mobility is necessary to better understand pathologies at the patellofemoral
joint. Patella mobility was assessed in 25 healthy individuals using a Patellostabilometer, a new
prototype instrument for quantification of the mediolateral patella displacement. The participants
underwent measurements of the mediolateral displacement three times using the Patellostabilome-
ter. A maximal force of 10 N was applied for patella movement. Additionally, leg length and
circumference of the knee, upper- and lower-leg were measured. Lateral patella displacement of
18.27 ± 3.76 mm (range 15.85–20.64 mm, interquartile range (IQR) of 4.79) was measured. The medial
patella displacement showed 24.47 ± 6.59 mm (range 19.29–29.76 mm, IQR of 10.47). The test–retest
measurement error was 2.32 ± 1.76 mm (IQR of 2.38 mm), with five outliers. There was greater
test–retest variability between the measurements of the medial displacement compared to the lateral
one. The test–retest variability reached 7% of the patella displacement. Other parameters provided no
significant correlations. Based on the natural patellofemoral mobility, a precise and clinically relevant
quantification of patella mobility is allowed.
Context awareness is critical for the successful execution of processes. In the abundance of business process management (BPM) research, frameworks exclusively devoted to extracting context from textual process data are scarce. With the deluge of textual data and its increasing value for organizations, it becomes essential to employ relevant text analytics techniques to increase the awareness of process workers, which is important for process execution. The present paper addresses this demand by developing a framework for context awareness based on process executions-related textual data using a well-established layered BPM context model. This framework combines and maps various text analytics techniques to the layers of the context model, aiming to increase the context awareness of process workers and facilitate informed decision-making. The framework is applied in an IT ticket processing case study. The findings show that contextual information obtained using our framework enriches the awareness of process workers regarding the process instance urgency, complexity, and upcoming tasks and assists in making decisions in terms of these aspects.
Compliance-Management
(2023)
Dieses Buch bietet eine komprimierte und praxisorientierte Einführung in die Grundlagen und Anforderungen eines Compliance-Managements, um den Leser schnell mit aktuellen und zentralen Regelungen vertraut zu machen. Dabei wird auf gesetzliche und regulatorische Bestimmungen ebenso eingegangen wie auf betriebswirtschaftliche Notwendigkeiten, um Mitarbeitende und Unternehmen vor den schwerwiegenden Folgen von Compliance-Verstößen zu schützen.
An approach for analyzing business process execution complexity based on textual data and event log
(2023)
With the advent of digital transformation, organizations increasingly rely on various information systems to support their business processes (BPs). Recorded data, including textual data and event log, expand exponentially, complicating decision-making and posing new challenges for BP complexity analysis in Business Process Management (BPM). Herein, Process Mining (PM) serves to derive insights based on historic BP execution data, called event log. However, in PM, textual data is often neglected or limited to BP descriptions. Therefore, in this study, we propose a novel approach for analyzing BP execution complexity by combining textual data serving as an input at the BP start and event log. The approach is aimed at studying the connection between complexities obtained from these two data types. For textual data-based complexity, the approach employs a set of linguistic features. In our previous work, we have explored the design of linguistic features favorable for BP execution complexity prediction. Accordingly, we adapt and incorporate them into the proposed approach. Using these features, various machine learning techniques are applied to predict textual data-based complexity. Moreover, in this prediction, we show the adequacy of our linguistic features, which outperformed the linguistic features of a widely-used text analysis technique. To calculate event log-based complexity, the event log and relevant complexity metrics are used. Afterward, a correlation analysis of two complexities and an analysis of the significant differences in correlations are performed. The results serve to derive recommendations and insights for BP improvement. We apply the approach in the IT ticket handling process of the IT department of an academic institution. Our findings show that the suggested approach enables a comprehensive identification of BP redesign and improvement opportunities.
Layered van der Waals ferromagnets, which preserve their magnetic properties down to exfoliated monolayers, are fueling an abundance of fundamental research and nanoscale device demonstration. CrGeTe3 is a prime example of this class of materials. Its temperature-pressure phase diagram features an insulator-to-metal transition and a significant increase in ferromagnetic Curie-Weiss temperatures upon entering the metallic state. We use density functional theory to understand the magnetic exchange interactions in CrGeTe3 at ambient and elevated pressures. We calculate Heisenberg exchange couplings, which provide the correct ferromagnetic ground state and explain the experimentally observed pressure dependence of magnetism in CrGeTe3. Furthermore, we combine density functional theory with dynamical mean-field theory to investigate the effects of electronic correlations and the nature of the high-pressure metallic state in CrGeTe3.
Large three-dimensional metallic parts can be printed layer-by-layer using gas metal arc directed energy deposition (GMA-DED) process at a high deposition rate and with little or no material wastage. Fast responsive real-time monitoring of GMA-DED process signatures and their transient variations is required for printing of dimensionally accurate and structurally sound parts. A systematic experimental investigation is presented here on multi-layer GMA-DED with two different scanning strategies using a high strength low alloy (HSLA) filler wire. The dynamic metal transfer, melt pool temperature field and its longitudinal cross-section, and arc voltage and current are monitored synchronously. The transient arc heat input and the melt pool solidification cooling rate are estimated from the monitored signals. The layer-wise variations of the melt pool dimension, surface temperature profile, thermal cycles, and solidification cooling rate are examined for different scanning strategies. It is comprehended that the part defects can be minimized, and the mass production of zero-defect parts can be achieved in GMA-DED process with synchronized monitoring and assessment of the real-time process signatures.
Unternehmen und Unternehmens-IT stehen im Zeitalter der Digitalisierung vor großen Umbrüchen. Geschäftsprozesse und die eingesetzten IT-Systemlandschaften verändern sich im schnellen Takt, teilweise werden erprobte Geschäftsmodelle disruptiv durch völlig neue Technologien ergänzt oder gar ersetzt. Dieses schnelllebige Umfeld erfordert eine intensive und qualitativ hochwertige Ausbildung der Mitarbeiter. Präsenzschulungen sind in Zeiten der Corona-Pandemie aber schwer zu realisieren. Wie eine praxisnahe und Fallstudien-basierte Ausbildung im ERP-Kontext trotzdem möglich ist, zeigt das E-Learning-basierte Programm erp4students der Technischen Hochschule Brandenburg am Beispiel von 13 Modulen im Umfeld neuester SAP-Technologien.
360-degree image and movie content has gained popularity over the media and the MICE (Meeting, Incentive, Conventions, and Exhibitions) industry in the last few years. There are three main reasons for this development. First, on the one hand, it is the immersive character of this media form, and, on the other hand, the development of recording and presentation technology has made significant progress in terms of resolution and quality. Third, after a decade of dynamic rising, the MICE Industry focuses on a disruptive change for more digital-based solutions. 360-degree panoramas are particularly widespread in VR and AR technology. However, despite the high immersive potential, these forms of presentation have the disadvantage that the users are isolated and have no social contact during the performance. Therefore, efforts have been made to project 360-degree content in specially equipped rooms or planetariums to enable a shared experience for the audience. One application area for 360-degree panoramas and films is conference rooms in hotels, conference centers, and any other venues that create an immersive environment for their clients to stimulate creativity. This work aims to overview the various application scenarios and usability possibilities for such conference rooms. In particular, we consider applications in construction, control, tourism, medicine, art exhibition, architecture, music performance, education, partying, organizing and carrying out events, and video conferencing. These applications and use scenarios were successfully tested, implemented, and evaluated in the 360-degree conference room “Dortmund” in the Hotel Park Soltau in Soltau, Germany. Finally, the advantages, challenges, and limitations of the proposed method are described.
When a droplet is brought in contact with an undercooled surface, it wets the substrate and solidifies at the same time. The interplay between the phase transition effects and the contact-line motion, leading to its arrest, remains poorly understood. Here we reveal the early solidification patterns and dynamics of spreading hexadecane droplets. Total internal reflection imaging is employed to temporally and spatially resolve the early solidification behavior. With this, we determine the conditions leading to the contact-line arrest. We quantify the overall nucleation behavior, i.e., the nucleation rate and the crystal growth speed and show its sensitivity to the applied undercooling of the substrate. We also show that for strong enough undercooling it is the rapid growth of the crystals which determines the eventual arrest of the spreading contact line. By combining the Johnson-Mehl-Avrami-Kolmogorov nucleation theory and scaling relations for the spreading, we calculate the temporal evolution of the solid area fraction, which is in good agreement with our observations.
„Ich will loslegen!“ (IWL). Dieser Ausruf spiegelt die Motivation der befragten Unternehmer*innen zu einem Zeitpunkt wider, an dem sie sich entschlossen haben, ein erstes oder neues Digitalisierungsprojekt zu initiieren. Um aktiv eine Unterstützung für das Vorhaben anzufragen, beantworteten kleinste, kleine und mittlere Unternehmen (KKMU) die 100 Fragen des IST-1-Fragebogens. Unsere IWL-Studie beinhaltet die Analyse der Antworten der Unternehmer*innen und ermöglicht neue Erkenntnisse. Sie zeigt Bedürfnisse und Widersprüche im Hinblick auf Digitalisierungsvorhaben auf. Wo setzen KKMU ihren Fokus, wie handeln sie und welche Potenziale und Hürden offenbaren sich im Kontext digitaler Lösungen? Die verschiedenen Punkte werden in der vorliegenden Fassung anhand von Hypothesen erläutert und abschließend diskutiert.
Selbstbestimmte Identitäten
(2021)
Anordnung des HmbBfDI gegen Facebook - Dringlichkeitsanordnung statt Zusammenarbeit und Kohärenz?
(2021)
Steganographic and covert communication is increasingly used for hiding attacks. Often information hiding is used by attackers in advanced persistent threats in order to operate without being noticed. Attackers might use it to hide data exfiltration or control channels for persistent malware. The paper analyzes potential threats to operational technology by investigating different communication protocols towards their suitability as cover channels. Using a generalized network architecture model and the communication flows of nuclear power plants, the attack potential using information hiding is exemplary assessed. An example for a supply chain attack for command injection is given on the foundation of the OPC UA protocol and an off-theshelf programmable logic controller. Subsequently, recommendations for a strategic and operational preparation for operators towards the prevention and detection of information hiding attacks are derived.
The paper presents our public Gait Analysis Data Base (http://gaitanalysis.th-brandenburg.de), which contains 3D walking kinematics and muscle activity data from healthy adults walking at normal, slow or fast pace on the flat ground or at an incremental speeds on treadmill. The acceleration, angular velocity and magnetic rate vectors are measured using XSens MTw sensors attached to both feet, shanks, thighs and the pelvis. EMG recordings are acquired using PLUX sEMG sensors applied at various leg muscles. The paper gives not only a detailed description of the data base, its webpage and the used terms (scenario, proband, experiment and trial), but also an overview about the experimental setup, the acquisition of data and the procedure of the experiments, the data processing and evaluation. Results of exemplary applications are described in the second part of the paper.
Kill Chain Attack Modelling for Hidden Channel Attack Scenarios in Industrial Control Systems
(2020)
The paper presents a public available dataset acquired with wearable inertial measurement units (Xsens MTw) in various walking scenarios. The database provides preprocessed recordings including acceleration, angular velocity and magnetic rate vectors as well as the orientation quaternions. The paper describes the gait measurement system including the whole process chain from the choice of the measurement principle and devices, the data acquisition, the data processing and post-processing. Possible faults and prevention methods are analyzed. Exemplary, indicators of their effect are introduced and discussed.
A central idea of ubiquitous music is that music does not arise from the ideas of an isolated genius, but rather from the interaction of several participants [Keller et al. 2014]. But this requires a certain amount of restraint on the part of the designers of the respective setting and at the same time seems to require a full disclosure of the underlying theoretical and aesthetic concepts to the participants, if the participants are really to be taken seriously and given the means to actually be able to become creative themselves in an understandable way within the given context. In this paper, the consequences of such a demand are first discussed theoretically. Finally, for the concept developed by the author, ”Every human being can compose on the basis of natural numbers”, an attempt is made in this specific case to determine in what form such a concept could be passed on in order to meet the above criteria.
Steganography embraces several hiding techniques which spawn across multiple domains. However, the related terminology is not unified among the different domains, such as digital media steganography, text steganography, cyber-physical systems steganography, network steganography (network covert channels), local covert channels, and out-of-band covert channels. To cope with this, a prime attempt has been done in 2015, with the introduction of the so-called hiding patterns, which allow to describe hiding techniques in a more abstract manner. Despite significant enhancements, the main limitation of such a taxonomy is that it only considers the case of network steganography. Therefore, this paper reviews both the terminology and the taxonomy of hiding patterns as to make them more general. Specifically, hiding patterns are split into those that describe the embedding and the representation of hidden data within the cover object. As a first research action, we focus on embedding hiding patterns and we show how they can be applied to multiple domains of steganography instead of being limited to the network scenario. Additionally, we exemplify representation patterns using network steganography.
Der Erwartungswert einer Zufallsgröße kann generell am Graphen ihrer Verteilungsfunktion durch eine naheliegende Gleichheit zweier Flächeninhalte festgelegt werden. Äquivalent dazu lässt er sich mit zwei uneigentlichen Riemann-Integralen darstellen. Davon ausgehend werden die Tschebyschow-Ungleichung und ihre Modifikation mit strikten Ungleichheitszeichen hergeleitet.
Smectic films in a collapsing catenoid develop spontaneous wrinkling patterns like solid sheets.
Smectic freely-suspended films can wrinkle like solid sheets. This has been demonstrated earlier with shape-fluctuating smectic bubbles. Here, we exploit the collapse of smectic catenoid films with a central equatorial film to expose the latter to rapid lateral compression. Wrinkle formation is observed in the planar film and the thickness dependence of the undulation wavelength is measured. In addition to the central film, its border undergoes an undulation instability as well.
Dieser Beitrag entwickelt ein Konzept zur praktischen Umsetzung eines Machine- Learning Verfahrens zum Lösen von Vehicle Routing Problemen im Kontext einer nachhaltigen “Letzte-Meile”-Logistik, welches durch einen Prototyp umgesetzt und getestet wurde. Der Prototyp basiert auf dem “Reinforcement Learning”-System und verwendet als Algorithmus “REINFORCE mit Baseline”. In einer Vergleichsanalyse wurde der Prototyp mit dem bekannten Vertreter Google-OR, anhand von zwei Anwendungsszenarien, verglichen. Der Prototyp überzeugt dabei in der Laufzeit und dem Automatismus. Es konnte festgestellt werden, dass eine Verwendung von Lernenden-Systemen für das Vehicle Routing Problem sich bei nur bei einem größeren Stoppvolumen und einer erweiterten IT-Infrastruktur empfiehlt.
A unified understanding of terms and their applicability is essential for every scientific discipline: steganography is no exception. Being divided into several domains (for instance, text steganography, digital media steganography, and network steganography), it is crucial to provide a unified terminology as well as a taxonomy that is not limited to some specific applications or areas. A prime attempt towards a unified understanding of terms was conducted in 2015 with the introduction of a pattern-based taxonomy for network steganography. Six years later, in 2021, the first work towards a pattern-based taxonomy for steganography was proposed. However, this initial attempt still faced several shortcomings, e.g., the lack of patterns for several steganography domains (the work mainly focused on network steganography and covert channels), various terminology issues, and the need of providing a tutorial on how the taxonomy can be used during engineering and scientific tasks, including the paper-writing process.</p>
<p>As the consortium who published this initial 2021-study on steganography patterns, in this paper we present the first comprehensive pattern-based taxonomy tailored to fit all known domains of steganography, including smaller and emerging areas, such as filesystem steganography and cyber-physical systems steganography. Besides, to make our contribution more effective and promote the use of the taxonomy to advance research on steganography, we also provide a thorough tutorial on its utilization. </p>
<p>Our pattern collection is available at <a href="https://patterns.ztt.hs-worms.de/" target="_blank">https://patterns.ztt.hs-worms.de</a>.</p>
Fast protein and metabolite liquid chromatography (FPLMC) was introduced years ago to enable the easy separation of high-molecular compounds such as proteins from small molecules and the identification of the low-molecular substances. In this paper, the method is applied for the rapid evaluation of freshness and monitoring the aging of animal meat and fish. A novel chromatographic sensor was developed with a deep UV LED-based photometric detection unit (255–265 nm), an original flow cuvette and registration scheme; the processing of a chromatogram with the sensor takes approximately 15 min. Strict isochronism between the elution of ATP metabolites, mainly hypoxanthine (Hx) and inosine monophosphate (IMP), and the time of maturation of meat or fish, was discovered. A new freshness index H* = [Hx]/[IMP] was introduced, which is proportional to the instrumental delay time in the FPMLC chromatograms: the H* index < 0.5 indicates the presence of inosine monophosphate (IMP) and the high quality of the meat or fish. Reasonably strong correlations were revealed between data obtained by FPMLC and total volatile basic nitrogen TVB-N (for fish) or volatile fatty acids VFA (for meat) content. Moreover, putative nucleotide salvage and an increase in the concentration of IMP were observed in fish after heat treatment using the FPMLC sensor and NMR technique.
A sample set of calculations is presented in this supplemental document to analytically estimate joint distortion for gas metal arc lap joining of aluminum and steel thin sheets following the published article "Analytical Estimation of Thermomechanical Distortion and Interface Layer Thickness for Gas Metal Arc Lap Joining of Dissimilar Sheets"
Due to the increasing number of complaints alleging privacy violations against companies to data protection authorities, the translation of business goals to system design goals and the subsequent consequences for customers’ privacy poses a challenge for many companies. For this reason, there is a need to bridge the economics of privacy and threats to privacy. To this end, our work relies on the concept of privacy as contextual integrity. This framework defines privacy as appropriate information flows subjected to social norms within particular social contexts or spheres. In this paper, we introduce a preliminary version of a semantic model which aims to relate and provide understanding on how well-established business goals may affect their customers’ privacy by designing IoT devices with permission access, data acquired by sensors, among other factors. Finally, we provide a use case application showing how to use the semantic model. The model aims to be an educational tool for professionals in business informatics during the modeling and designing process of a product which may gather sensitive data or may infer sensitive information, giving an understanding of the interaction of the product and its footprint with diverse actors (humans or machines). In the future, a further complete model of the presented may also target other groups, such as law enforcement bodies, as part of their educational training in such systems.
4.1.: Grundlagen
(2022)
4.2.: Sicherheit
(2023)
Der vorliegende Beitrag befasst sich mit den Herausforderungen, die im Rahmen von Remote Work
in Kooperationen bezüglich der Informations- und
IT-Sicherheit bestehen, insbesondere im Hinblick auf
den sicheren Datenaustausch. Des Weiteren wird die
Wichtigkeit einer ganzheitlichen Sicht von IT-Governance-, Risiko- und Compliance-Management in Verbünden kleiner und mittlerer Unternehmen (KMU)
behandelt. Weiterhin wird aufgezeigt, was bei der
informationstechnischen Absicherung von Kooperationen und IT-Konsortien beachtet werden sollte.
In dieser Forschung wird es gezeigt, wie sicher und benutzerfreundlich eine Authentifizierung mit Passkey/FIDO2 auf Ebene des Web-Browsers ist, im Vergleich zu einer Authentifizierung mit einem starken Passwort oder eine Authentifizierung aus einer Kombination von einem Passwort und einer Zwei-Faktor-Authentifizierung.
In der heutigen digitalisierten Welt spielt die Sicherheit von IT-Infrastrukturen eine
entscheidende Rolle. Diese Bachelorarbeit untersucht das Potenzial von Network
Access Control (NAC) als eine IT-Lösung zur Verbesserung der Netzwerksicherheit in
modernen IT-Umgebungen. Dabei steht die Zugriffskontrolle von Personen und
Geräten im Vordergrund. Damit soll erreicht werden, dass unautorisierter Zugriff zum
Netzwerk verhindert wird. Es werden die Begrifflichkeiten, Funktionsweise und
potenzielle Angriffsvektoren von NAC untersucht. Des Weiteren werden die jeweiligen
Funktionen der NAC-Produkte macmon und der Open-Source Lösung PacketFence
gegenübergestellt. Im praktischen Teil der Arbeit werden dann die vorgestellten
Angriffsvektoren an einem Test-Netzwerk durchgeführt und analysiert.
Die Arbeit zeigt, dass NAC eine wichtige Komponente in der Zugriffskontrolle für eine
moderne IT-Infrastruktur ist. Während einige Angriffe auf das Test-Netzwerk
abgewehrt werden konnten, war es dennoch möglich, sich als Angreifer am Netzwerk
anzumelden. NAC ist ein unerlässliches Tool für größere IT-Infrastrukturen, jedoch
erfordert eine korrekte Konfiguration und effektive Nutzung von NAC ein
umfangreiches Wissen über die verschiedenen Aspekte und Themenbereiche der
Netzwerksicherheit.
Untersuchung der Rotorfestigkeit von permanenterregten Synchronmaschinen mit vergrabenen Magneten
(2023)
Diese Projektarbeit behandelt die mechanische Simulation der Rotoren von permanenterregten Synchronmaschinen für den Festigkeitsnachweis. Hierzu wird die Finite-Elemente-Methode mit dem Programm CalculiX verwendet. Als Beispiel wird der Elektromotor des Toyota Prius II im Detail betrachtet. Hierbei werden die unterschiedlichen Lasten modelliert, dazu zählen neben der Zentrifugalkraft auch der Innendruck durch eine Presspassung sowie die elektromagnetischen Kräfte. Für die Modellierung von Kräften auf der Rotoroberfläche wird eine Methodik zur Umsetzung in CalculiX entwickelt und anhand eines Beispielmodells demonstriert. Der angestrebte Festigkeitsnachweis kann im Rahmen dieser Arbeit erbracht werden. Weiterhin wird gezeigt, dass der Einfluss der elektromagnetischen Kräfte im Arbeitspunkt mit der höchsten Drehzahl sehr gering ausfällt. Insgesamt bietet diese Arbeit die Grundlagen für mechanische Modellierungen von Rotoren unter Berücksichtigung aller Kräfte. Dies kann direkt auf andere Elektromotoren angewendet werden.
Einsicht in die Abläufe und Leistung heutiger Software und verteilter Systeme zu erlangen, wird durch stetig steigende Komplexität zunehmend erschwert. Die Firma Peterson Technologies GmbH implementierte zur Linderung dieser Problematik ein internes Telemetriesystem. Ziel dieser Arbeit ist es, das System auf Wunsch der Firma durch ein neues zu ersetzen, um so die Überwachung zu verbessern und aktuellere Software zu verwenden. Nach einer Untersuchung des vorherigen Systems werden Prioritäten festgelegt, welche die spätere Nutzung, Instandhaltung und Erweiterung des neuen Systems erleichtern sollen. Darauf folgen die Planung seiner Architektur, die Auswahl und Implementierung der Software und schließlich das Erzeugen einer einfachen Dokumentation. Der resultierende Telemetriestack ist funktionstüchtig und erfüllt die Vorstellungen der Firma. Dennoch weist er einige Probleme, wie beispielsweise eine hohe CPU Belastung auf, welche zusammen mit Möglichkeiten der Verbesserung und Erweiterung abschließend betrachtet werden.
Single dielectric microspheres can manipulate light focusing and collection to enhance optical interaction with surfaces. To demonstrate this principle, we experimentally investigate the enhancement of the Raman signal collected by a single dielectric microsphere, with a radius much larger than the exciting laser spot size, residing on the sample surface. The absolute microsphere-assisted Raman signal from a single graphene layer measured in air is more than a factor of two higher than that obtained with a high numerical aperture objective. Results from Mie’s theory are used to benchmark numerical simulations and an analytical model to describe the isolated microsphere focusing properties. The analytical model and the numerical simulations justify the Raman signal enhancement measured in the microsphere-assisted Raman spectroscopy experiments.
Biomass gasification is recognized as a viable avenue to accelerate the sustainable production of hydrogen. In this work, a numerical simulation model of air gasification of rice husks is developed using the Aspen Plus to investigate the feasibility of producing hydrogen-rich syngas. The model is experimentally validated with rice husk gasification results and other published studies. The influence of temperature and equivalence ratio on the syngas composition, H2 yield, LHVSyngas, H2/CO ratio, CGE, and PCG was studied. Furthermore, the synchronized effects of temperature and ER are studied using RSM to determine the operational point of maximizing H2 yield and PCG. The RSM analysis results show optimum performance at temperatures between 820 °C and 1090 °C and ER in the range of 0.06–0.10. The findings show that optimal operating conditions of the gasification system can be achieved at a more refined precision through simulations coupled with advanced optimization techniques.
Glass-ceramic composites consisting of potassium-iron-silicate glass and barium titanate mixed in various proportions were successfully synthesized by low-temperature sintering. The crystal structure of the obtained composite samples, the porosity and the microhardness were studied by the X-ray diffraction, the electron microscopy, the weight method, and the Vickers method. Electrical characteristics (dielectric permittivity, tunability and losses) of as-prepared and annealed in oxygen medium samples were investigated at microwaves. According to structural analysis, the synthesized samples are a mixture of KFeSi glass, ferroelectric BaTiO3, and dielectric barium polytitanates; the ratio of the latter determines the electrical properties of the composites. Depending on the content of barium titanate, the studied composite samples show a permittivity from 50 to 270 with a dielectric loss level of 0,1–0,02 in frequency range from 3 to 10 GHz. Annealing of composite samples in an oxygen-containing environment leads to an increase in their dielectric permittivity and tunability by 10–25% and a twofold decrease in dielectric loss.
Companies are increasingly facing the challenges of a persistent cyber threat landscape. By means of AI, cyber attacks can be efficiently conducted more successful through offensive AI. As for cyber defense, AI can be also utilized against cyber threats (defensive AI). Due to limited resources, especially in small and medium-sized companies (SMEs), there is a need to deploy more effective defensive cyber security solutions. Precisely, the adaptation of AI-based resilient defenses must be driven forward. Therefore, the aim of this paper is to identify and evaluate AI-related use cases with a high impact potential on the cyber security level, while being applicable to SMEs at the same time. In order to reach the research goal, an extensive literature review of several online catalogs, surveys and online platforms was conducted. In conclusion, seven crucial AI-based security features were outlined that are providing a high impact potential to the security level for SMEs. Afterwards, the results are discussed and set into a broader context. Even though AI-based security solutions are providing a large range of advantages, certain challenges and barriers using AI-related security applications are addressed in the paper as well. A high need for usable state of the art AI based cyber security solution for SMEs was identified.
How do we interact with the digital world in the future by only using our thoughts to interact? To interact with the digital world, we use gestures (most common: swipe gestures), voice, facial expressions and mental commands. The latter has become more important by recent press releases about scientific achievements, for example, from Neuralink [1] using invasive technology to control a computer game by thoughts only [2]. Another study says an application can display text on a screen by just thinking about a word [3]. Currently, BCIs are mainly developed for neurotechnology and healthcare. However, it is a question of time when these services will be available for commercial products for everyday life. (Until then, manufacturers have to minimize health risks and face privacy and safety regulations.) The thesis is that in the future, you will be able to interact with your digital devices just by using your thoughts and you’ll do much faster. This makes sense in many situations where you f. e. do not have a free hand (manufacturing, sports) or cannot speak (underwater). But for such services, you cannot rely on conventional visual design guidelines or interaction patterns, frameworks or libraries. Navigation interacting with a digital service by mental command has a lot of advantages, the human brain comes naturally with some specific features that force us to find a radically new way to interact with digital interfaces. The following study introduces you first into working conditions with mental commands, comparing invasive and non-invasive technologies, and later on comparing several possibilities of interaction patterns for a BCI of everyday usage. [1] Neuralink is a US neurotechnology company founded in July 2016 by Elon Musk and eight other persons. Neuralink’s goal is to develop a device for communication between human brain and computers, a so-called brain-computer-interface(BCI). [2] The Guardian, Fr. 9th April 2021 “Elon Musk startup shows monkey with brain chip implants playing video game”. https://www.theguardian.com/technology/2021/apr/09/elon-musk- neuralink-monkey-video-game . [3] Scientific American, 15th July 2021, Neuroscience, author Emily Willingham: “New Brain Implant Transmits Full Words from Neural Signals”.
Making and interpretation of drawings and schematics is an important skill to be developed in engineering education. The question type STACK in the Moodle learning management system combined with the interactive graphics library JSXGraph has a great potential for implementation of e-learning resources addressing these skills in formative and summative settings. The authoring process of such materials is complex due to multiple markup and programming languages like HTML, LaTeX, Maxima and JavaScript (JS) being involved. The Meclib concept mitigates this complexity and allows for efficient bulk production of material with consistent appearance and user experience. The core of Meclib is a set of pre-defined JSXGraph-based objects with an interface to Maxima, such that no problem specific JS code is required at all. The present paper outlines the basic ideas of the implementation and demonstrates the approach for some typical examples of different complexity. The focus is on applications in engineering mechanics, starting from static illustrations up to an editor for free body diagrams, with rich adaptive formative feedback.
In this study we have examined the potential of excess wind use in Germany. Excess wind constitutes roughly 40% of unused capacities of installed wind power in Germany. Using LP modelling and representative annual load profiles on an hourly resolution, we investigate the impact of the price level for wind peak power supply of residential quarters with heat, cold and electricity in Germany in combination with different power ratios of wind supply and demand. As we show, an application of wind peak tariff is technically and economically feasible and allows using green leftover energy without going in competition with e.g., green fuels or green H2 production.
This study analyzes approaches to decarbonize the energy supply of the secondary steel processing industry. Therefore, real data from a secondary steel production company is used in combination with state-of-the art low carbon energy supply technologies. Also, the use of waste heat from a pusher furnace for process integration is considered. The developed temporal process model allows holistic optimizing and expanding the steel making process system regarding techno-economic criteria. As we show, implementing the annual heat demand of a municipality shows that a nearly 100 % self-sufficient heat supply is possible.
SMath with Maxima
(2023)
SMath Studio mit Maxima
(2020)
Die Versionierung von Daten ist ein hochkomplexes Problem, das viele verschiedene
Aspekte berücksichtigen muss. Daher ist in diesem Bereich bisher noch kein univer-
sell anwendbarer Ansatz beschrieben worden. Verschiedene Autoren haben sich an einer
Lösung versucht und Herangehensweisen für ihre eigenen Anwendungsfälle entwickelt.
In dieser Arbeit wird ein neuer Ansatz anhand eines Fallbeispiels vorgestellt. Der An-
satz zielt darauf ab, Daten- und Versionierungsstrukturen in einem relationalen Da-
tenmodell zu vereinigen und dabei eine einfache Integration von Geschäftsprozessen
zu ermöglichen. Insbesondere wird darauf geachtet, dass die Erzwingung des korrekten
Ablaufs von Geschäftsprozessen durch eine maschinelle Umsetzung derselben möglich
ist. Das Datenmodell beinhaltet eine vollständige Versionierungshistorie in Form eines
gerichteten zyklenlosen Graphen. Hiermit bietet es eine breit anwendbare Lösung zur
Datenversionierung, die zudem gut in bestehende Abläufe und Datensätze integrierbar
ist. In dieser Arbeit wird das kombinierte Datenmodell vorgestellt und anhand von ge-
nerischen Beispielen erläutert. Zudem wird die Funktionalität des Ansatzes anhand des
Fallbeispiels der Verwaltung der Studiengangscurricula des Fachbereichs Informatik und
Medien der Technischen Hochschule Brandenburg belegt. Hierbei wird auch die Integra-
tion von Geschäftsprozessen und die Nutzbarkeit in der tatsächlichen Datenverwaltung
dargestellt.
Diese Bachelorarbeit untersucht die Einbindung eines typischen Endnutzer Netzwerkgerätes in ein bestehendes Protokollierungssystem. Aufgrund des erhöhten Anteils an Mitarbeitern im Homeoffice in deutschen Firmen sind die Heimnetzwerke ein bedeutend wichtigerer Bestandteil der Firmensicherheit und es soll untersucht werden, wie übliche Heimnetzwerkgeräte in die Sicherheitsstrukturen der Firmen eingebunden werden können.
Zu diesem Zweck wird ein Proof-of-Concept basierend auf den Technologien TR-064, zur Kommunikation mit der FRITZ!Box und Syslog, zur Kommunikation mit einem Protokollierungssystem entwickelt.
Anhand dieses Prototypen lässt sich feststellen, dass eine solche Einbindung zwar einfach umzusetzen ist, aber auf dieser keine effektive Überwachung aufgebaut werden kann. Die Ursache dafür ist der Umstand, dass TR-064 nur einen Bruchteil der Logdaten von der FRITZ!Box zurücksendet.
Das Umfragedesign "LLM-Readiness" - Gruppen- und Einzelumfrage unter Erstsemesterstudierenden der HWR Berlin im Wintersemester 2022/2023 - ergänzt die Publikation "Kritische Reflexion und Handlungsansätze zum Einsatz Generativer KI in der Wirtschaftsinformatik, welche zur Jahrestagung des AKWI im September 2023 eingereicht wird.
Ransomware-Angriffe auf Kritische Infrastrukturen, wie Energie- oder Wasserversorgung, treten immer häufiger auf und stellen eine große Bedrohung für die Betreiber und die Bevölkerung dar. Eine verlässliche und frühzeitige Erkennung dieser Angriffe ist somit ein wichtiger Bestandteil von IT-Sicherheitskonzepten.
Ziel dieser Arbeit ist die Klärung der Fragen, welche Methoden zur Erkennung von Ransomware eingesetzt werden und welche Indikatoren für Ransomware-Angriffe mithilfe eines Angriffserkennungssystems in einer nachgebildeten IT-KRITIS-Infrastruktur erkannt werden können.
Es wurden Methoden zur Detektion von Malware und Ransomware genauer betrachtet.
In einem Experiment wurde die Erkennung von Ransomware mithilfe eines Angriffserkennungssystems (Elastic Stack) untersucht. Das Ergebnis dieser Arbeit zeigt, dass die Erkennung sowohl mit allgemeinen Detektionsansätzen als auch mit auf Ransomware spezialisierten Methoden erfolgen kann.
Aus dem Experiment geht hervor, dass die Detektion von Ransomware-Angriffen mithilfe eines Angriffserkennungssystems in der Praxis erfolgreich ist. Indikatoren für RansomwareAngriffe werden sowohl auf Systemebene (Prozesse, Dateioperationen, Registry-Änderungen etc.) als auch auf Netzwerkebene (C2-Kommunikation, auffällige DNS-Anfragen, IPAdressen etc.) erkannt.
Der Einfluss von Technik in der Medizin wird immer deutlicher. Hierbei steigt auch im gleichen Maß die Bedrohung auf das Gesundheitswesen durch Cyberkriminalität. [1] Diese Arbeit umfasst eine Schwachstellenbetrachtung und Analyse der Kommunikation zweier B. Braun Infusionspumpen und dem dazugehörigen Konfigurationswerkzeug, der „Online-Suite“. Hierbei wurde ein Fokus auf vor allem drei Untersuchungsmethoden gelegt: 1. Ein Portscan mittels „Nmap“, welcher bereits erste, leicht einsehbare Informationen über die verwendeten Ports und Dienste aufdecken sollte. 2. Ein Schwachstellenscan durchgeführt mit „GVM/OpenVAS“, welcher die einzelnen Schwachstellen der Dienste und Software an Hand von einem „CVSS-Wert“ bewertet. 3. Eine Betrachtung des Netzwerkverkehrs in Wireshark, um den Aufbau der Kommunikation zu analysieren. Hierbei ergaben sich diverse Sicherheitsrisiken und Probleme. Diese können im schlimmsten Fall auch die Sicherheit des Patienten beeinflussen. Besonders häufig wurden hierbei Schwachstellen gefunden, welche durch veraltete und nicht weiter unterstützte Software bedingt waren.