3,833 research outputs found
The malleability of political attitudes : Choice blindness, confabulation and attitude change
This thesis is an empirical and theoretical investigation of choice blindness, in particular in the domain of political attitudes. Choice blindness is a cognitive phenomenon in which people do not notice dramatic mismatches between what they choose and what they get while still offering seemingly introspective arguments to explain their (putative) choice. In four papers, it is demonstrated that the effect also applies to salient political attitudes and evaluations of political candidates. All studies took place in close connection to real elections, and new tools building of the underlying choice blindness methodology has been developed to collect the data. Further, the potential downstream effects are explored, such as influence on voting intentions, and lasting attitude changes. The potential mechanisms behind the effect are also investigated and confabulatory reasoning stands out as an important part in facilitating the observed attitude changes
Inverse modelling of GNSS multipath for sea level measurements - initial results
We present a new method to retrieve sea level from GNSS SNR
data that relies upon inverse modelling of the detrended SNR. This method can simultaneously use data from both GPS and GLONASS, and both L1 and L2 frequencies, to improve the
solution with respect to prior studies. Results from the GNSS-R installation at Onsala Space Observatory are presented and the retrieved sea level heights are compared with a co-located pressure mareograph. The method is found to give an RMS error of 1.8 cm. The results are also compared against previous implementations of GNSS tide gauges and found to have lower RMS than both the earlier SNR algorithm and also the dual receiver, phase delay method
Ground-based GNSS-R solutions by means of software defined radio
Usually ground-based GNSS-R installations are either existing geodetic GNSS stations or they are built with dedicated components that enable the deduction and monitoring of physical and geometrical properties of the reflecting area around that particular site. In both cases, hardware components usually enable real-time operation of such instruments. However, as software-defined radio (SDR) technology has advanced in the recent years it is now possible to carry out signal processing in real-time, which makes it an ideal candidate for the realization of a flexible GNSS-R system. It is shown how SDR can help to realize GNSS-R solutions for sea-level monitoring at the Onsala Space Observatory, Sweden. Moreover, such SDR solutions can be mounted on an unmanned aerial vehicle (UAV) in order to collect data from higher altitudes and even provide Delay-Doppler information for extended GNSS-R studies
Improving GNSS-R sea level determination through inverse modeling of SNR data
This paper presents a new method for retrieving sea surface heights from Global Navigation Satellite Systems reflectometry (GNSS-R) data by inverse modeling of SNR observations from a single geodetic receiver. The method relies on a B-spline representation of the temporal sea level variations in order to account for its continuity. The corresponding B-spline coefficients are determined through a nonlinear least squares fit to the SNR data, and a consistent choice of model parameters enables the combination of multiple GNSS in a single inversion process. This leads to a clear increase in precision of the sea level retrievals which can be attributed to a better spatial and temporal sampling of the reflecting surface. Tests with data from two different coastal GNSS sites and comparison with colocated tide gauges show a significant increase in precision when compared to previously used methods, reaching standard deviations of 1.4 cm at Onsala, Sweden, and 3.1 cm at Spring Bay, Tasmania
Lifting the Veil of Morality: Choice Blindness and Attitude Reversals on a Self-Transforming Survey
Every day, thousands of polls, surveys, and rating scales are employed to elicit the attitudes of humankind. Given the ubiquitous use of these instruments, it seems we ought to have firm answers to what is measured by them, but unfortunately we do not. To help remedy this situation, we present a novel approach to investigate the nature of attitudes. We created a self-transforming paper survey of moral opinions, covering both foundational principles, and current dilemmas hotly debated in the media. This survey used a magic trick to expose participants to a reversal of their previously stated attitudes, allowing us to record whether they were prepared to endorse and argue for the opposite view of what they had stated only moments ago. The result showed that the majority of the reversals remained undetected, and a full 69% of the participants failed to detect at least one of two changes. In addition, participants often constructed coherent and unequivocal arguments supporting the opposite of their original position. These results suggest a dramatic potential for
flexibility in our moral attitudes, and indicates a clear role for self-attribution and post-hoc rationalization in attitude formation and change
3D Hydrophobic Moment Vectors as a Tool to Characterize the Surface Polarity of Amphiphilic Peptides
AbstractThe interaction of membranes with peptides and proteins is largely determined by their amphiphilic character. Hydrophobic moments of helical segments are commonly derived from their two-dimensional helical wheel projections, and the same is true for β-sheets. However, to the best of our knowledge, there exists no method to describe structures in three dimensions or molecules with irregular shape. Here, we define the hydrophobic moment of a molecule as a vector in three dimensions by evaluating the surface distribution of all hydrophilic and lipophilic regions over any given shape. The electrostatic potential on the molecular surface is calculated based on the atomic point charges. The resulting hydrophobic moment vector is specific for the instantaneous conformation, and it takes into account all structural characteristics of the molecule, e.g., partial unfolding, bending, and side-chain torsion angles. Extended all-atom molecular dynamics simulations are then used to calculate the equilibrium hydrophobic moments for two antimicrobial peptides, gramicidin S and PGLa, under different conditions. We show that their effective hydrophobic moment vectors reflect the distribution of polar and nonpolar patches on the molecular surface and the calculated electrostatic surface potential. A comparison of simulations in solution and in lipid membranes shows how the peptides undergo internal conformational rearrangement upon binding to the bilayer surface. A good correlation with solid-state NMR data indicates that the hydrophobic moment vector can be used to predict the membrane binding geometry of peptides. This method is available as a web application on http://www.ibg.kit.edu/HM/
Organic farming and biodiversity - the impact of organic farming on nature
Organic farming is generally acknowledged for its positive effects on biodiversity and other landscape services. However, the intensity of farming has changed significantly through the last decade as ranks of traditional holistic organic farmers have been joined by much more economically-driven new organic farmers. At the same time there have also been steady improvements in farming methodology and crop types resulting in efficiency in organic farming which can often rival its conventional counterparts. Therefore, large variations occur between organic farms
Resilient Shield: Reinforcing the Resilience of Vehicles Against Security Threats
Vehicles have become complex computer systems with multiple communication interfaces. In the future, vehicles will have even more connections to e.g., infrastructure, pedestrian smartphones, cloud, road-side-units and the Internet. External and physical interfaces, as well as internal communication buses have shown to have potential to be exploited for attack purposes. As a consequence, there is an increase in regulations which demand compliance with vehicle cyber resilience requirements. However, there is currently no clear guidance on how to comply with these regulations from a technical perspective.To address this issue, we have performed a comprehensive threat and risk analysis based on published attacks against vehicles from the past 10 years, from which we further derive necessary security and resilience techniques. The work is done using the SPMT methodology where we identify vital vehicle assets, threat actors, their motivations and objectives, and develop a comprehensive threat model. Moreover, we develop a comprehensive attack model by analyzing the identified threats and attacks. These attacks are filtered and categorized based on attack type, probability, and consequence criteria. Additionally, we perform an exhaustive mapping between asset, attack, threat actor, threat category, and required mitigation mechanism for each attack, resulting in a presentation of a secure and resilient vehicle design. Ultimately, we present the Resilient Shield a novel and imperative framework to justify and ensure security and resilience within the automotive domain
REMIND: A Framework for the Resilient Design of Automotive Systems
In the past years, great effort has been spent on enhancing the security and safety of vehicular systems. Current advances in information and communication technology have increased the complexity of these systems and lead to extended functionalities towards self-driving and more connectivity. Unfortunately, these advances open the door for diverse and newly emerging attacks that hamper the security and, thus, the safety of vehicular systems. In this paper, we contribute to supporting the design of resilient automotive systems. We review and analyze scientific literature on resilience techniques, fault tolerance, and dependability. As a result, we present the REMIND resilience framework providing techniques for attack detection, mitigation, recovery, and resilience endurance. Moreover, we provide guidelines on how the REMIND framework can be used against common security threats and attacks and further discuss the trade-offs when applying these guidelines
- …