Offenburg University of Applied Sciences
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Optimization of MIMO Radar Antenna Arrays for Precise and Reliable 2D Direction-of-Arrival Estimation
No full textMultiple-input multiple-output (MIMO) radar systems enhance two-dimensional (2D) direction-of-arrival (DOA) estimation through virtual arrays. However, their performance depends on optimizing the array geometry for both accuracy and robustness. This paper introduces a method for optimizing MIMO arrays by integrating the Cramér-Rao Bound (CRB) and angular ambiguity function (AF) analysis, as both metrics critically contribute to DOA estimation performance. In this work, the CRB is minimized to enhance local estimation accuracy, while sidelobe levels (SLL) in the field of view are suppressed to avoid ambiguities across all possible DOAs. The performance of the optimized array is evaluated using maximum likelihood (ML) and multiple signal classification (MUSIC) estimators across a range of signal-to-noise ratios (SNRs), demonstrating the effectiveness of the proposed metrics in the design process
Evaluating the potential of agile branding: opportunities and challenges in the start-up context
Get PDFThe necessity for companies to adopt an agile brand management approach to maintain relevance and competitiveness in our dynamic and fast-moving world is a key finding of recent studies. Nevertheless, no study has yet investigated the potential and applicability of the concept of agile branding. Concurrently, start-ups are confronted with the challenge of high failure rates due to shortcomings in brand management. The necessity for start-ups to adopt innovative and dynamic brand strategies arises from the constant internal and external changes that characterise the start-up environment. Previous studies on brand management, by contrast, have mainly focussed on established companies. Given the affinity and need for agility observed in start-ups, agile branding appears to be particularly relevant for start-ups. This study aims to address two research gaps: firstly, to explore the potential of the concept of agile branding and, secondly, to expand academic research of branding practices tailored to start-ups to assist them in overcoming the specific brand management challenges they face. The study draws on an extensive and structured literature review, followed by qualitative semi-structured interviews with eleven experts and 18 start-ups, to discuss the opportunities and challenges of agile branding in the context of start-ups. The results were analysed from the perspective of the five dimensions of agile branding and the dynamic capabilities framework. Agile branding offers start-ups the opportunity to adapt swiftly to market changes, allocate resources efficiently, and reduce risk through data-driven decision-making. Overcoming challenges requires a shift in organisational culture and employee mindset, optimisation of stakeholder feedback processes, and navigation of the complexities of implementation. In conclusion, the advantages of agile branding for start-ups are found to outweigh the disadvantages. The study extends the scarce research on agile branding and provides brand managers and start-up founders with an efficient approach to organising their brand management process with limited resources
Second-order nonlinear mixing processes involving a leaky guided acoustic wave
No full textQuasi-phasematched mixing processes of acoustic waves via second-order nonlinearity are analyzed with two perfectly guided waves generating a leaky wave. The efficiency of such processes is quantified by an acoustic nonlinearity parameter (ANP), defined as the linear growth rate of the leaky wave’s amplitude in the initial stage of its spatial evolution. Two approximate ways of estimating the ANP of such processes are suggested. The first starts from a stationary solution of the equation of motion and boundary conditions for the displacement field, obtained within perturbation theory. This approach requires the solution of a near-singular linear system of equations. The second is based on the resonant state expansion of the displacement field generated in the mixing process. It allows to express the ANP in the form of an overlap integral, requiring normalization of the displacement field associated with the leaky wave. For leaky output waves with a high degree of localization at the waveguide, both methods yield results in good agreement, as demonstrated for an example system with generalized (2D) plate modes. The first approach has also been applied to finite element calculations of the ANP for nonlinear mixing processes of (1D) edge waves in an elastic plate with rigid faces
Verfahren zum Maximieren der von einer analogen Entropiequelle abgeleiteten Entropie (DE102022110360B4)
No full textVerfahren zum Erzeugen einer Sicherheitskennung, wobei das Verfahren folgende Schritte aufweist:- Maximieren der von einer analogen Entropiequelle abgeleiteten Entropie durch ein Verfahren zum Maximieren der von einer analogen Entropiequelle abgeleiteten Entropie, wobei das Verfahren zum Maximieren der von einer analogen Entropiequelle abgeleiteten Entropie ein Bereitstellen von Eingabedaten für die analoge Entropiequelle (2), ein Erzeugen von Rückgabewerten durch die analoge Entropiequelle basierend auf den Eingabedaten (3), und ein Gruppieren der Rückgabewerte aufweist, wobei das Gruppieren der Rückgabewerte ein Anwenden von Versätzen auf Rückgabewerte aufweist, und- Erzeugen der Sicherheitskennung basierend auf der erzeugten maximierten Entropie (8), wobei die analoge Entropiequelle eine Physical Unclonable Function oder eine biometrische Quelle ist, und wobei das Anwenden von Versätzen ein Einteilen von Rückgabewerten in dieselbe Gruppe, obwohl der Abstand zwischen den entsprechenden Rückgabewerten kleiner als ein entsprechender Grenzwert für den Abstand zwischen zwei Rückgabewerten ist, indem Versätze eingeführt werden, so dass es erscheint, als würde der Abstand zwischen den entsprechenden Rückgabewerten dem entsprechenden Grenzwert für den Abstand zwischen zwei Rückgabewerten entsprechen, aufweist