1,745 research outputs found

    Sample4Geo: Hard Negative Sampling For Cross-View Geo-Localisation

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    Cross-View Geo-Localisation is still a challenging task where additional modules, specific pre-processing or zooming strategies are necessary to determine accurate positions of images. Since different views have different geometries, pre-processing like polar transformation helps to merge them. However, this results in distorted images which then have to be rectified. Adding hard negatives to the training batch could improve the overall performance but with the default loss functions in geo-localisation it is difficult to include them. In this article, we present a simplified but effective architecture based on contrastive learning with symmetric InfoNCE loss that outperforms current state-of-the-art results. Our framework consists of a narrow training pipeline that eliminates the need of using aggregation modules, avoids further pre-processing steps and even increases the generalisation capability of the model to unknown regions. We introduce two types of sampling strategies for hard negatives. The first explicitly exploits geographically neighboring locations to provide a good starting point. The second leverages the visual similarity between the image embeddings in order to mine hard negative samples. Our work shows excellent performance on common cross-view datasets like CVUSA, CVACT, University-1652 and VIGOR. A comparison between cross-area and same-area settings demonstrate the good generalisation capability of our model

    Wie sollte die Hochschulpolitik reformiert werden?

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    Impact of the introduction of decoupled payments on functioning of the German land market: Country report of the EU tender Study on the functioning of land markets in those EU member states influenced by measures applied under the Common Agricultura

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    Against the background of the reform of the Common Agricultural Policy (CAP) in 2003 the following analysis, brings into focus the responses of the agricultural sector to decoupled subsidies. In particular it addresses the impact of the Single Payment Scheme (SPS) on land sales and rent prices and therefore on farm structure. It also aims to assess the extent to which the reform advances sound and sustainable agriculture and provides incentives for marketorientated farming practices. The study is based on the analysis of statistical data and expert surveys conducted in three selected regions. -- G E R M A N V E R S I O N: Die vorliegende Studie untersucht den Einfluss der 2003 im Zuge der Reform der Gemeinsamen Agrarpolitik (GAP) durchgeführten Entkopplung der Direktzahlungen auf den Agrarsektor in Deutschland. Besonderer Fokus der Analyse liegt auf der Auswirkung der einmaligen Zahlungen auf die Kauf- und Pachtpreise für das landwirtschaftlich genutzte Land. Des Weiteren wird die Förderung einer nachhaltigen und marktorientierten Landwirtschaft durch die GAP-Reform bewertet. Die Untersuchung basiert auf Auswertung statistischer Daten und auf Expertenbefragungen, welche in drei ausgewählten Bundesländern durchgeführt wurden.Land markets,midterm review,CAP,structural change,Bodenmärkte,Halbzeitbewertung,GAP,Strukturwandel

    Orientation-Guided Contrastive Learning for UAV-View Geo-Localisation

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    Retrieving relevant multimedia content is one of the main problems in a world that is increasingly data-driven. With the proliferation of drones, high quality aerial footage is now available to a wide audience for the first time. Integrating this footage into applications can enable GPS-less geo-localisation or location correction. In this paper, we present an orientation-guided training framework for UAV-view geo-localisation. Through hierarchical localisation orientations of the UAV images are estimated in relation to the satellite imagery. We propose a lightweight prediction module for these pseudo labels which predicts the orientation between the different views based on the contrastive learned embeddings. We experimentally demonstrate that this prediction supports the training and outperforms previous approaches. The extracted pseudo-labels also enable aligned rotation of the satellite image as augmentation to further strengthen the generalisation. During inference, we no longer need this orientation module, which means that no additional computations are required. We achieve state-of-the-art results on both the University-1652 and University-160k datasets

    Violent Behavior During Psychiatric Inpatient Treatment in a German Prison Hospital

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    Violent behavior in correctional facilities is common and differs substantially in type, target, implication, and trigger. Research on frequency and characteristics of violent behavior in correctional facilities and psychiatric hospitals is limited. Results from recent research suggest that comorbidity of severe mental disorder, personality disorder, and diagnosis of substance abuse is related to a higher risk of violent behavior. In the Berlin prison hospital, a database was created to collect data from all violent incidences (n=210) between 1997 and 2006 and between 2010 and 2016. In a retrospective, case-control study, we analyzed specific socioeconomic data and psychiatric diagnosis and compared the group of prisoners with violent behavior with randomly selected prisoners of the same department without violent behavior (n = 210). Diagnosis of schizophrenia, non-German nationality, no use of an interpreter, no children, and no previous sentence remained significantly associated with the dependent variable violent behavior. There were no significant differences regarding age and legal statuses. Practical implications for clinical work are discussed

    Zur Lepidopteren- und Syrphiden- Fauna der FND "Kalkfluren" und "Bläulings-Biotop" bei Lieskau (Saalkreis) im Raum Halle

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    .The fauna of Lepidoptera and Syrphidae of the investigation area is characterised by a high percentage of indigenous species of xerothermic shrub biotopes. The number of species preferring dry grassland habitats is low and includes low individual numbers too. As management measures we propose partial removing of shrubs and especially black pine trees. Sixty three of the whole 319 recorded Macrolepidoptera species were involved into a indicator group to control the further development of Lepidopterataxocoenosis. Fifty three Lepidoptera species are protected by law and 42 species are included in the red data list. Despite the incompleteness of the faunistic records especially in hoverflies they are useful to evaluate the protected biotopes

    Sensitivity of Bunker Cave to climatic forcings highlighted through multi-annual monitoring of rain-, soil-, and dripwaters

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    The last two decades have seen a considerable increase in studies using speleothems as archives of past climate variability. Caves under study are now monitored for a wide range of environmental parameters and results placed in context with speleothem data. The present study investigates trends from a seven year long monitoring of Bunker Cave, northwestern Germany, in order to assess the hydraulic response and transfer time of meteoric water from the surface to the cave. Rain-, soil-, and dripwater were collected from August 2006 to August 2013 at a monthly to bimonthly resolution and their oxygen and hydrogen isotope composition was measured. Furthermore, drip rates were quantified. Due to different drip characteristics, annual mean values were calculated for the drip rates of each drip site. Correlations of the annual mean drip rate of each site with precipitation and infiltration demonstrate that the annual infiltration, and thus the annual precipitation control the inter-annual drip-rate variability for all except one site. The hydraulic response is not delayed on an annual basis. All drip sites display identical long-term trends, which suggests a draining of a common karst reservoir over these seven years of monitoring. Correlations of soil- and dripwater monthly δ18O and δD values with atmospheric temperature data reveal water transfer times of 3 months to reach a depth of 40 cm (soilwater at site BW 2) and 4 months for 70 cm depth (soilwater at site BW 1). Finally, the water reaches the cave chambers (15 to 30 m below land surface) after ca. 2.5 years. Consequently, a temporal offset of 29 to 31 months (ca. 2.5 years) between the hydraulic response time (no time lag on annual basis) and the water transfer time (time lag of 29 to 31 months) was found, which is negligible with regard to Bunker Cave speleothems because of their slow growth rates. Here, proxies recording precipitation/infiltration and temperature are registered on a decadal scale. Variations in drip rate and thus precipitation and infiltration are recorded by δ13C and Mg/Ca ratios in speleothem calcite. Speleothem δ18O values reflect both temperature and precipitation signals due to drip rate-related fractionation processes. We document that long-term patterns in temperature and precipitation are recorded in dripwater patterns of Bunker Cave and that these are linked to the North Atlantic Oscillation (NAO)

    Editorial

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    Magnetic resonance imaging (MRI) at ultra-high magnetic field strengths offers an increased signal-to-noise ratio (SNR) and has the potential to boost the MR image resolution. Cardiovascular applications remain challenging, as high-resolution image acquisitions are still too slow to capture a fast moving organ like the heart. Synchronisation of the acquisition to the heart motion is necessary to acquire an image over several consecutive heartbeats. The current gold-standard method for cardiac synchronisation is the electrocardiogram (ECG), which measures the electrical activity of the heart. Magnetohydrodynamic effects of the blood flow interfere with the ECG measurement and can affect reliable gating, which is particularly significant at higher magnetic field strengths. The work of this thesis presents new motion estimation methods that are based on radiofrequency (RF) scattering of a parallel-transmit coil and directly assess the heart motion, independent of the electrical activity of the heart. A cardiac motion signal is derived with a high SNR and with a number of potential gating features, which have a high accuracy when compared to ECG gating. No additional motion-monitoring hardware is needed other than the commercially available pTx system. Different RF pulse designs are proposed to integrate the scattering measurements into the normal MR image acquisition to estimate cardiac and respiratory motion in real-time on the MRI scanner. The integrated cardiac-respiratory motion framework is combined with a new MR imaging acquisition strategy to acquire high-resolution, 3D images of the heart during free breathing.</p
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