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Road surface roughness is a major factor that is responsible for the skid resistance of vehicles and, thus, road safety. Therefore, it needs to be monitored regularly to ensure that the roughness values are in the optimal range and to perform maintenance actions when needed. Synthetic aperture radar (SAR) backscatter is sensitive to surface roughness and can provide large-scale estimates of road surface roughness. In this letter, a semiempirical model for estimating road surface roughness using high-resolution spaceborne X-band SAR datasets from Germany’s TerraSAR-X (TS-X) satellite is proposed for the first time. The method is capable of handling the low signal-to-noise ratio (SNR) of spaceborne SAR. To enhance the reliability of the results obtained from rather low SNR datasets, techniques, such as SNR thresholding, multi-dataset fusion, and automatic road extraction, were implemented. The study’s results show good agreement with ground-truth (GT) data. [ABSTRACT FROM AUTHOR]

The treatise of the Swiss philosopher and jurist Emer de Vattel, The Law of Nations (1758), is well known in the United States and has attracted sustained scholarly attention. Against the widespread assumption that the reception of The Law of Nations in America only started in 1775, this article establishes that Vattel's treatise was available on American soil already in 1762. This finding paves the way for inquiry into Vattel's intellectual authority in the revolutionary context from the early pamphleteers to the Declaration of Independence. Following a reception-based methodology that facilitates robust inferences from patterns of intertextuality, this study aims to make up for the gap in Vattel's historiography regarding the crucial period between 1762 and 1776. New England, and the Boston area in particular, turn out to be the hotbeds of Vattel's reception. A special emphasis is put on the central role of John Adams as a transmitter of Vattel's thought in the colonial discourse in spring 1776. In the great political documents of this time, most of which were written by Adams or by patriots close to him, such as Richard Henry Lee, a recurrent argument, called the Vattel-Adams argument, was put forth, forging a claim on the loss of royal protection into a justification of secession. The present study demonstrates that this rationalization bears unmistakably Vattelian marks. Furthermore, considering Thomas Jefferson's mastery of intertextual practice, it is argued that the first, second, and fifth paragraphs of the Declaration can be robustly shown to contain both immediately Vattelian hypotext and Lockean hypotext mediated by Vattel. Beyond its objective of uncovering a hitherto neglected aspect of the revolution's intellectual underpinnings, this study offers a new perspective on the intertextual complexity and density that characterize the political documents of the revolutionary era. [ABSTRACT FROM AUTHOR]

This article builds on V.O. Key’s postulate that voters are not fools and that they function as an echo chamber reflecting the clarity of alternatives presented to them. We first propose a reassessment of Key’s claim by examining whether and to what extent the impact of issue preferences on the vote choice depends on the clarity of parties’ profile on these issues. Our empirical tests are based on data from the 2007 Swiss election study and cover three different issues that voters may use as decision-making criteria. Our results confirm that the clearer a party’s profile on a given issue, the higher the impact of that issue on the vote for the party. Second, we offer a refinement of Key’s argument by arguing that voters’ political sophistication conditions the strength of issue voting. Empirical evidence supports this argument, but shows that the effect of political sophistication is curvilinear: sophistication exerts a stronger mediating role when a party has a moderately clear profile than when it has a low or high profile. [ABSTRACT FROM PUBLISHER]