Modeling WLAN Received Signal Strengths Using Gaussian Process Regression on the Sodindoorloc Dataset

While any wireless technology can be used for indoor localization purposes, WLANhas the advantage of having a huge existing infrastructure. A radio map that matches specific locations to received signal strength is needed, to enable most of these indoor localization methods. To create these radio maps, with enough detail to achieve sufficient localization accuracy, is expensive and time consuming. Therefore, methods to interpolate and extrapolate more detailed maps from sparse radio maps are being developed. One recent approach is to use Gaussian process regression. Even though some papers already studied Gaussian process regression, most studied only the basic model with zero mean and squared exponential kernel. In addition, when the model fit was evaluated in more detail, the experimental area was of limited complexity. Hence, this thesis evaluates the fit of Gaussian process regression, in a more complex indoor environment, based on adequate model metrics and analysis of the plots of the predicted mean and standard deviation functions. As a conclusion, the most suitable model is presented, as well as the reasoning why it was chosen

New data on direct ion storage dosemeters

The DIS-1 dosemeter from the Finnish company RADOS is an innovative kind of passive electronic dosemeter for photon and beta radiation. This study examines the ‘long-term' linear response behaviour, the calibration and readout accuracy with large samples of ‘used' DIS-1 dosemeters especially in the low-dose region, which is of special interest for radiation protection issues. Our measurements prove the adequacy of the DIS-1 dosemeter for long-term-personal dosimetry. The fast and precise readout seems to make the DIS-1 dosemeter an ideal choice for personal dosimetry in low-dose environment

Nuclear stopping and flow in heavy ion collisions and the in-medium NN cross section

We present transport calculations for heavy ion reactions in which the mean field and the in-medium nucleon-nucleon cross section are consistently based on the same effective interaction, i.e. the in-medium T-matrix from microscopic Dirac-Brueckner calculations. Doing so, the stopping in central reactions in terms of the recently proposed $var_{\rm tl}$ observable and the correlation to the behavior of the directed flow is investigated. The relation to the nuclear shear viscosity is discussed.Comment: 9 pages, 4 figure

HySpecNet-11k: A Large-Scale Hyperspectral Dataset for Benchmarking Learning-Based Hyperspectral Image Compression Methods

The development of learning-based hyperspectral image compression methods has recently attracted great attention in remote sensing. Such methods require a high number of hyperspectral images to be used during training to optimize all parameters and reach a high compression performance. However, existing hyperspectral datasets are not sufficient to train and evaluate learning-based compression methods, which hinders the research in this field. To address this problem, in this paper we present HySpecNet-11k that is a large-scale hyperspectral benchmark dataset made up of 11,483 nonoverlapping image patches. Each patch is a portion of 128 $\times$ 128 pixels with 224 spectral bands and a ground sample distance of 30 m. We exploit HySpecNet-11k to benchmark the current state of the art in learning-based hyperspectral image compression by focussing our attention on various 1D, 2D and 3D convolutional autoencoder architectures. Nevertheless, HySpecNet-11k can be used for any unsupervised learning task in the framework of hyperspectral image analysis. The dataset, our code and the pre-trained weights are publicly available at https://hyspecnet.rsim.berlinComment: Accepted at IEEE International Geoscience and Remote Sensing Symposium (IGARSS) 2023. The dataset, our code and the pre-trained weights are publicly available at https://hyspecnet.rsim.berli

Asymmetric Colliding Nuclear Matter Approach in Heavy Ion Collisions

The early stage of a heavy ion collision is governed by local non-equilibrium momentum distributions which have been approximated by colliding nuclear matter configurations, i.e. by two Lorentz elongated Fermi ellipsoids. This approach has been extended from the previous assumption of symmetric systems to asymmetric 2-Fermi sphere configurations, i.e. to different densities. This provides a smoother transition from the limiting situation of two interpenetrating currents to an equilibrated system. The model is applied to the dynamical situations of heavy ion collisions at intermediate energies within the framework of relativistic transport (RBUU) calculations. We find that the extended colliding nuclear matter approach is more appropriate to describe collective reaction dynamics in terms of flow observables, in particular, for the elliptic flow at low energies.Comment: 21 pages, 8 figures, accepted for publication in Nuclear Physics

Do patients with gastroesophageal reflux disease and somatoform tendencies benefit from antireflux surgery?

Source at http://dx.doi.org/10.3748/wjg.v25.i3.388.BACKGROUND - The clinical presentation of gastroesophageal reflux disease (GERD) shows a large symptom variation also in different intensities among patients. As several studies have shown, there is a large overlap in the symptomatic spectrum between proven GERD and other disorders such as dyspepsia, functional heartburn and/or somatoform disorders. AIM - To prospectively evaluate the GERD patients with and without somatoform disorders before and after laparoscopic antireflux surgery. METHODS - In a tertiary referral center for foregut surgery over a period of 3 years patients with GERD, qualifying for the indication of laparoscopic antireflux surgery, were investigated prospectively regarding their symptomatic spectrum in order to identify GERD and associated somatoform disorders. Assessment of symptoms was performed by an instrument for the evaluation of somatoform disorders [Somatoform Symptom Index (SSI) > 17]. Quality of life was evaluated by Gastrointestinal Quality of Life Index (GIQLI). RESULTS - In 123 patients an indication for laparoscopic antireflux surgery was established and in 43 patients further medical therapy was suggested. The portion of somatoform tendencies in the total patient population was 20.48% (34 patients). Patients with a positive SSI had a preoperative GIQLI of 77 (32-111). Patients with a normal SSI had a GIQLI of 105 (29-140) (P P < 0.0043). CONCLUSION - Patients with GERD and associated somatoform disorders have significantly worse levels of quality of life. The latter patients can also benefit from laparoscopic fundoplication, however they will not reach a normal level

Gastrointestinal Quality of Life in Gastroesophageal Reflux Disease: A Systematic Review

Background: The Gastrointestinal Quality of Life Index (GIQLI) is a well-established instrument for the assessment of quality of life (QOL) in gastrointestinal (GI) diseases. The purpose of this literature review was to investigate QOL by means of GIQLI in patients with gastroesophageal reflux disease (GERD) prior to any interventional therapy. There are several reports on GIQLI data; however, comparisons from different countries and/or different GERD cohorts assessing the same disease have to date not been conducted. Methods: The GIQLI uses 36 items around 5 dimensions (GI symptoms [19 items], emotional dimension [5 items], physical dimension [7 items], social dimension [4 items], and therapeutic influences [1 item]). A literature search was conducted on the application of GIQLI in GERD patients prior to interventional therapy using reports in PubMed. Data on the mean GIQLI as well as index data for the 5 dimensions as originally validated were extracted from the published patient cohorts. A comparison with the normal healthy control group from the original publication of the GIQLI validation conducted by Eypasch was performed. Data are presented descriptively as GIQLI points as well as a reduction from 100% maximum possible index points (max 144 index points = highest QOL). Results: In total, 77 abstracts from studies using the GIQLI on patients with GERD were identified. After screening for content, 21 publications were considered for further analysis. Ten studies in GERD patients comprised complete calculations of all dimensions and were included in the analysis. Data from 1,682 study patients were evaluated with sample sizes ranging from 33 to 568 patients (median age of 789 females and 858 males: 51.8 years). The median overall GIQLI for the patient group was 91.7 (range 86–102.4), corresponding to 63.68% of the maximum GIQLI. The dimensions with the largest deviation from the respective maximum score were the physical dimension (55% of maximum) followed by the emotional dimension (60% of maximum). In summary, the GIQLI level in GERD cohorts was reduced to 55–75% of the maximum possible index. Conclusions: Severe GERD causes substantial reductions in the patient’s QOL. The level of GIQLI can carry between different studied GERD cohorts from different departments and countries. GIQLI can be used as an established tool to assess the patient’s condition in various dimensions

Quality of life in benign colorectal disease—a review of the assessment with the Gastrointestinal Quality of Life Index (GIQLI)

Background and purpose The Gastrointestinal Quality of Life Index (GIQLI) is an instrument for the assessment of qual‑ ity of life (QOL) in diseases of the upper and lower GI tract, which is validated in several languages around the world. The purpose of this literature review is the assessment of the GIQLI in patients with benign colorectal diseases. Reports on GIQLI data are collected from several institutions, countries, and different cultures which allows for comparisons, which are lacking in literature. Methods The GIQL Index uses 36 items around 5 dimensions (gastrointestinal symptoms (19 items), emotional dimension (5 items), physical dimension (7 items), social dimension (4 items), and therapeutic influences (1 item). The literature search was performed on the GIQLI and colorectal disease, using reports in PubMed. Data are presented descriptively as GIQL Index points as well as a reduction from 100% maximum possible index points (max 144 index points=highest quality of life). Results The GIQLI was found in 122 reports concerning benign colorectal diseases, of which 27 were finally selected for detailed analysis. From these 27 studies, information on 5664 patients (4046 female versus 1178 male) was recorded and summarized. The median age was 52 years (range 29–74.7). The median GIQLI of all studies concerning benign colorectal disease was 88 index points (range 56.2–113). Benign colorectal disease causes a severe reduction in QOL for patients down to 61% of the maximum. Conclusions Benign colorectal diseases cause substantial reductions in the patient’s QOL, well documented by GIQLI, which allows a comparison QOL with other published cohorts

Fragment Formation in Central Heavy Ion Collisions at Relativistic Energies

We perform a systematic study of the fragmentation path of excited nuclear matter in central heavy ion collisions at the intermediate energy of $0.4 AGeV$. The theoretical calculations are based on a Relativistic Boltzmann-Uehling-Uhlenbeck ($RBUU$) transport equation including stochastic effects. A Relativistic Mean Field ($RMF$) approach is used, based on a non-linear Lagrangian, with coupling constants tuned to reproduce the high density results of calculations with correlations. At variance with the case at Fermi energies, a new fast clusterization mechanism is revealed in the early compression stage of the reaction dynamics. Fragments appear directly produced from phase-space fluctuations due to two-body correlations. In-medium effects of the elastic nucleon-nucleon cross sections on the fragmentation dynamics are particularly discussed. The subsequent evolution of the primordial clusters is treated using a simple phenomenological phase space coalescence algorithm. The reliability of the approach, formation and recognition, is investigated in detail by comparing fragment momentum space distributions {\it and simultaneously} their yields with recent experimental data of the $FOPI$ collaboration by varying the system size of the colliding system, i.e. its compressional energy (pressure, radial flow). We find an excellent agreement between theory and experiment in almost all the cases and, on the other hand, some limitations of the simple coalescence model. Furthermore, the temporal evolution of the fragment structure is explored with a clear evidence of an earlier formation of the heavier clusters, that will appear as interesting $relics$ of the high density phase of the nuclear Equation of State ($EoS$).Comment: 21 pages, 8 figures, Latex Elsart Style, minor corrections in p.7, two refs. added, Nucl.Phys.A, accepte