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The RSNA Abdominal Traumatic Injury CT (RATIC) dataset is the largest publicly available collection of adult abdominal CT studies annotated for traumatic injuries. This dataset includes 4,274 studies from 23 institutions across 14 countries. The dataset is freely available for non-commercial use via Kaggle at https://www.kaggle.com/competitions/rsna-2023-abdominal-trauma-detection. Created for the RSNA 2023 Abdominal Trauma Detection competition, the dataset encourages the development of advanced machine learning models for detecting abdominal injuries on CT scans. The dataset encompasses detection and classification of traumatic injuries across multiple organs, including the liver, spleen, kidneys, bowel, and mesentery. Annotations were created by expert radiologists from the American Society of Emergency Radiology (ASER) and Society of Abdominal Radiology (SAR). The dataset is annotated at multiple levels, including the presence of injuries in three solid organs with injury grading, image-level annotations for active extravasations and bowel injury, and voxelwise segmentations of each of the potentially injured organs. With the release of this dataset, we hope to facilitate research and development in machine learning and abdominal trauma that can lead to improved patient care and outcomes., Comment: 40 pages, 2 figures, 3 tables

This dataset is composed of cervical spine CT images with annotations related to fractures; it is available at https://www.kaggle.com/competitions/rsna-2022-cervical-spine-fracture-detection/.

While it is well known that population differences from genetics, sex, race, and environmental factors contribute to disease, AI studies in medicine have largely focused on locoregional patient cohorts with less diverse data sources. Such limitation stems from barriers to large-scale data share and ethical concerns over data privacy. Federated learning (FL) is one potential pathway for AI development that enables learning across hospitals without data share. In this study, we show the results of various FL strategies on one of the largest and most diverse COVID-19 chest CT datasets: 21 participating hospitals across five continents that comprise >10,000 patients with >1 million images. We also propose an FL strategy that leverages synthetically generated data to overcome class and size imbalances. We also describe the sources of data heterogeneity in the context of FL, and show how even among the correctly labeled populations, disparities can arise due to these biases.

The need to predict acoustic propagation through marine sediments that contain gas bubbles has become increasingly important for civil engineering and climate studies. There are relatively few in situ acoustic wave propagation studies of muddy intertidal sediments, in which bubbles of biogenic gas (generally methane, a potent greenhouse gas) are commonly found. We used a single experimental rig to conduct two in situ intertidal acoustical experiments to improve understanding of acoustic remote sensing of gassy sediments, eventually including gas bubble size distributions. In the first experiment, we measured sediment sound speed and attenuation between four aligned hydrophones for a quasi-plane wave propagating along the array. The second experiment involved a focused insonified sediment volume created by two transducers emitting coincident sound beams at different frequencies that generated bubble-mediated acoustic signals at combination frequencies. The results from sediment core analyses, and comparison of in situ acoustic velocity and attenuation values with those of water-saturated sediments, together provide ample evidence for the presence of in situ gas bubbles in the insonified volumes of sediments. These datasets are suitable for linear and non-linear inversion studies that estimate in situ greenhouse gas bubble populations, needed for future acoustical remote sensing applications.

The need to predict acoustic propagation through marine sediments that contain gas bubbles has become increasingly important for civil engineering and climate studies. There are relatively few in situ acoustic wave propagation studies of muddy intertidal sediments, in which bubbles of biogenic gas (generally methane, a potent greenhouse gas) are commonly found. We used a single experimental rig to conduct two in situ intertidal acoustical experiments to improve understanding of acoustic remote sensing of gassy sediments, eventually including gas bubble size distributions. In the first experiment, we measured sediment sound speed and attenuation between four aligned hydrophones for a quasi-plane wave propagating along the array. The second experiment involved a focused insonified sediment volume created by two transducers emitting coincident sound beams at different frequencies that generated bubble-mediated acoustic signals at combination frequencies. The results from sediment core analyses, and comparison of in situ acoustic velocity and attenuation values with those of water-saturated sediments, together provide ample evidence for the presence of in situ gas bubbles in the insonified volumes of sediments. These datasets are suitable for linear and non-linear inversion studies that estimate in situ greenhouse gas bubble populations, needed for future acoustical remote sensing applications.

This thesis investigates the acoustic wave propagation in bubbly liquids as part of the SONO project supported by the FP7 European Commission programme, which is aimed at developing a pilot sonochemical plant in order to produce antibacterial medical textile fabrics by coating of the textile with ZnO or CuO nanoparticles. The findings of this research are anticipated to aid the design procedures and also to provide better understanding of the micro scale physical and chemical events. Propagation of acoustic pressure waves in a bubbly liquid is modelled by using Helmholtz equation in this thesis. Computational models are developed based on meshless approaches, i.e. radial basis integral equation (RBIE) and local boundary integral equation (LBIE) methods. A major part of the research focuses on improving the efficiency and the accuracy of the developed methods. For this purpose, numerical tests are carried out with several example problems in order to cross-verify the applicability of the methods. As a result of these tests, the optimal parameters which should be used to minimize the numerical error are suggested. Further, strategies are proposed in order to handle the thin inclusions, such as textile fabric, in the domain. The wave propagation in bubbly liquids involves coupled effects of the sound field and bubble population field, such as dissipation of the acoustic energy by bubble oscillations. The problem is therefore non-homogeneous due to presence of bubbles and nonlinear due to coupled effects. The governing equations, derived from linearized or nonlinear theories, can be found in the literature. Examples of both linear and nonlinear wave propagation are solved in this study. Results related to a 3D sonoreactor including textile fabric are also presented. Effects of bubble size distribution and bubble volume fraction on the acoustic wave propagation are discussed in the example problems.

This thesis investigates the acoustic wave propagation in bubbly liquids as part of the SONO project supported by the FP7 European Commission programme, which is aimed at developing a pilot sonochemical plant in order to produce antibacterial medical textile fabrics by coating of the textile with ZnO or CuO nanoparticles. The findings of this research are anticipated to aid the design procedures and also to provide better understanding of the micro scale physical and chemical events. Propagation of acoustic pressure waves in a bubbly liquid is modelled by using Helmholtz equation in this thesis. Computational models are developed based on meshless approaches, i.e. radial basis integral equation (RBIE) and local boundary integral equation (LBIE) methods. A major part of the research focuses on improving the efficiency and the accuracy of the developed methods. For this purpose, numerical tests are carried out with several example problems in order to cross-verify the applicability of the methods. As a result of these tests, the optimal parameters which should be used to minimize the numerical error are suggested. Further, strategies are proposed in order to handle the thin inclusions, such as textile fabric, in the domain. The wave propagation in bubbly liquids involves coupled effects of the sound field and bubble population field, such as dissipation of the acoustic energy by bubble oscillations. The problem is therefore non-homogeneous due to presence of bubbles and nonlinear due to coupled effects. The governing equations, derived from linearized or nonlinear theories, can be found in the literature. Examples of both linear and nonlinear wave propagation are solved in this study. Results related to a 3D sonoreactor including textile fabric are also presented. Effects of bubble size distribution and bubble volume fraction on the acoustic wave propagation are discussed in the example problems.

A demonstrator setup of a customized receiver antenna, a multi-input low noise block down-converter (MLNB) is presented in this paper. This antenna concept is based on a reflector feed array reception antenna for satellite Ku-band broadcast reception. In specific circumstances the Ku-band broadcast reception can be subject to interference form adjacent satellites give the customer demand for compact and easy to install reception antennas suitable for direct-to-home (DTH) reception. In this context a compact 45cm Ku-band reception antenna with coherent 3-element feed has been defined according to specific reception system requirements for broadcast system and setup and tested in the context of the ESA ARTES 5.2 Project. The demonstrator consist of an antenna prototype conceived by FTA Inverto for coherent reception of 3 feeds and a beamforming chipset from ASTRON operating in L-band and based on an NXP SiGe technology and chipset processes as well as beamforming control software from SES TechCom. Antenna measurements in a compact antenna test range (CATR) as well as over satellite demonstrate the achievable reception gain re-configurability which permits to adapt the broadcast antenna front end to different reception scenarios. The demonstrated benefits to satellite broadcast reception are to first provide an antenna system to mitigate adjacent satellite interference via reconfigure antenna gain nulling, second provide an antenna system for reception of any desired satellite signal within a given azimuth opening angle as well as third provide assistance at installation via an auto-fine-pointing procedure. This paper presents the demonstrator setup and justifies and explains the design choices in the context of the framing commercial requirements. Furthermore the antenna simulations and measurement results are presented here in view of the technical specification defined. The antenna re-configurability and control procedures are presented as well as the related reconf, QC 20121114

A demonstrator setup of a customized receiver antenna, a multi-input low noise block down-converter (MLNB) is presented in this paper. This antenna concept is based on a reflector feed array reception antenna for satellite Ku-band broadcast reception. In specific circumstances the Ku-band broadcast reception can be subject to interference form adjacent satellites give the customer demand for compact and easy to install reception antennas suitable for direct-to-home (DTH) reception. In this context a compact 45cm Ku-band reception antenna with coherent 3-element feed has been defined according to specific reception system requirements for broadcast system and setup and tested in the context of the ESA ARTES 5.2 Project. The demonstrator consist of an antenna prototype conceived by FTA Inverto for coherent reception of 3 feeds and a beamforming chipset from ASTRON operating in L-band and based on an NXP SiGe technology and chipset processes as well as beamforming control software from SES TechCom. Antenna measurements in a compact antenna test range (CATR) as well as over satellite demonstrate the achievable reception gain re-configurability which permits to adapt the broadcast antenna front end to different reception scenarios. The demonstrated benefits to satellite broadcast reception are to first provide an antenna system to mitigate adjacent satellite interference via reconfigure antenna gain nulling, second provide an antenna system for reception of any desired satellite signal within a given azimuth opening angle as well as third provide assistance at installation via an auto-fine-pointing procedure. This paper presents the demonstrator setup and justifies and explains the design choices in the context of the framing commercial requirements. Furthermore the antenna simulations and measurement results are presented here in view of the technical specification defined. The antenna re-configurability and control procedures are presented as well as the related reconf, QC 20121114

A demonstrator setup of a customized receiver antenna, a multi-input low noise block down-converter (MLNB) is presented in this paper. This antenna concept is based on a reflector feed array reception antenna for satellite Ku-band broadcast reception. In specific circumstances the Ku-band broadcast reception can be subject to interference form adjacent satellites give the customer demand for compact and easy to install reception antennas suitable for direct-to-home (DTH) reception. In this context a compact 45cm Ku-band reception antenna with coherent 3-element feed has been defined according to specific reception system requirements for broadcast system and setup and tested in the context of the ESA ARTES 5.2 Project. The demonstrator consist of an antenna prototype conceived by FTA Inverto for coherent reception of 3 feeds and a beamforming chipset from ASTRON operating in L-band and based on an NXP SiGe technology and chipset processes as well as beamforming control software from SES TechCom. Antenna measurements in a compact antenna test range (CATR) as well as over satellite demonstrate the achievable reception gain re-configurability which permits to adapt the broadcast antenna front end to different reception scenarios. The demonstrated benefits to satellite broadcast reception are to first provide an antenna system to mitigate adjacent satellite interference via reconfigure antenna gain nulling, second provide an antenna system for reception of any desired satellite signal within a given azimuth opening angle as well as third provide assistance at installation via an auto-fine-pointing procedure. This paper presents the demonstrator setup and justifies and explains the design choices in the context of the framing commercial requirements. Furthermore the antenna simulations and measurement results are presented here in view of the technical specification defined. The antenna re-configurability and control procedures are presented as well as the related reconf, QC 20121114

A demonstrator setup of a customized receiver antenna, a multi-input low noise block down-converter (MLNB) is presented in this paper. This antenna concept is based on a reflector feed array reception antenna for satellite Ku-band broadcast reception. In specific circumstances the Ku-band broadcast reception can be subject to interference form adjacent satellites give the customer demand for compact and easy to install reception antennas suitable for direct-to-home (DTH) reception. In this context a compact 45cm Ku-band reception antenna with coherent 3-element feed has been defined according to specific reception system requirements for broadcast system and setup and tested in the context of the ESA ARTES 5.2 Project. The demonstrator consist of an antenna prototype conceived by FTA Inverto for coherent reception of 3 feeds and a beamforming chipset from ASTRON operating in L-band and based on an NXP SiGe technology and chipset processes as well as beamforming control software from SES TechCom. Antenna measurements in a compact antenna test range (CATR) as well as over satellite demonstrate the achievable reception gain re-configurability which permits to adapt the broadcast antenna front end to different reception scenarios. The demonstrated benefits to satellite broadcast reception are to first provide an antenna system to mitigate adjacent satellite interference via reconfigure antenna gain nulling, second provide an antenna system for reception of any desired satellite signal within a given azimuth opening angle as well as third provide assistance at installation via an auto-fine-pointing procedure. This paper presents the demonstrator setup and justifies and explains the design choices in the context of the framing commercial requirements. Furthermore the antenna simulations and measurement results are presented here in view of the technical specification defined. The antenna re-configurability and control procedures are presented as well as the related reconf, QC 20121114

A demonstrator setup of a customized receiver antenna, a multi-input low noise block down-converter (MLNB) is presented in this paper. This antenna concept is based on a reflector feed array reception antenna for satellite Ku-band broadcast reception. In specific circumstances the Ku-band broadcast reception can be subject to interference form adjacent satellites give the customer demand for compact and easy to install reception antennas suitable for direct-to-home (DTH) reception. In this context a compact 45cm Ku-band reception antenna with coherent 3-element feed has been defined according to specific reception system requirements for broadcast system and setup and tested in the context of the ESA ARTES 5.2 Project. The demonstrator consist of an antenna prototype conceived by FTA Inverto for coherent reception of 3 feeds and a beamforming chipset from ASTRON operating in L-band and based on an NXP SiGe technology and chipset processes as well as beamforming control software from SES TechCom. Antenna measurements in a compact antenna test range (CATR) as well as over satellite demonstrate the achievable reception gain re-configurability which permits to adapt the broadcast antenna front end to different reception scenarios. The demonstrated benefits to satellite broadcast reception are to first provide an antenna system to mitigate adjacent satellite interference via reconfigure antenna gain nulling, second provide an antenna system for reception of any desired satellite signal within a given azimuth opening angle as well as third provide assistance at installation via an auto-fine-pointing procedure. This paper presents the demonstrator setup and justifies and explains the design choices in the context of the framing commercial requirements. Furthermore the antenna simulations and measurement results are presented here in view of the technical specification defined. The antenna re-configurability and control procedures are presented as well as the related reconf, QC 20121114

In orthogonal frequency-division multiplexing (OFDM) systems operating over rapidly time-varying channels, the orthogonality between subcarriers is destroyed leading to inter-carrier interference (ICI) and resulting in an irreducible error floor. In this paper, a new and low-complexity maximum {\em a posteriori} probability (MAP) detection algorithm is proposed for OFDM systems operating over rapidly time-varying multipath channels. The detection algorithm exploits the banded structure of the frequency-domain channel matrix whose bandwidth is a parameter to be adjusted according to the speed of the mobile terminal. Based on this assumption, the received signal vector is decomposed into reduced dimensional sub-observations in such a way that all components of the observation vector contributing to the symbol to be detected are included in the decomposed observation model. The data symbols are then detected by the MAP algorithm by means of a Markov chain Monte Carlo (MCMC) technique in an optimal and computationally efficient way. Computational complexity investigation as well as simulation results indicate that this algorithm has significant performance and complexity advantages over existing suboptimal detection and equalization algorithms proposed earlier in the literature., Comment: 6 pages, 4 figures