Directional antennas improve the link-connectivity of interference limited ad hoc networks

We study wireless ad hoc networks in the absence of any channel contention or transmit power control and ask how antenna directivity affects network connectivity in the interference limited regime. We answer this question by deriving closed-form expressions for the outage probability, capacity and mean node degree of the network using tools from stochastic geometry. These novel results provide valuable insights for the design of future ad hoc networks. Significantly, our results suggest that the more directional the interfering transmitters are, the less detrimental are the effects of interference to individual links. We validate our analytical results through computer simulations.Comment: 6 pages, 7 figures, conference proceedings of PIMRC'201

Privacy in Multimodal Federated Human Activity Recognition

Human Activity Recognition (HAR) training data is often privacy-sensitive or held by non-cooperative entities. Federated Learning (FL) addresses such concerns by training ML models on edge clients. This work studies the impact of privacy in federated HAR at a user, environment, and sensor level. We show that the performance of FL for HAR depends on the assumed privacy level of the FL system and primarily upon the colocation of data from different sensors. By avoiding data sharing and assuming privacy at the human or environment level, as prior works have done, the accuracy decreases by 5-7%. However, extending this to the modality level and strictly separating sensor data between multiple clients may decrease the accuracy by 19-42%. As this form of privacy is necessary for the ethical utilisation of passive sensing methods in HAR, we implement a system where clients mutually train both a general FL model and a group-level one per modality. Our evaluation shows that this method leads to only a 7-13% decrease in accuracy, making it possible to build HAR systems with diverse hardware.Comment: In 3rd On-Device Intelligence Workshop at MLSys 2023, 8 page

Endoscopic ultrasonography in large gastric folds

Large gastric folds are seen in a great number of benign and malignant conditions. Diagnosis is a clinical challenge because the etiology may be extremely varied and standard biopsies are often inconclusive. The gastric wall is considered thickened at endosonography when it is more than 3.6 mm in width. Different diseases show different levels of infiltration of the gastric wall. When abnormalities involve the second layer only, benign conditions can be considered and standard endoscopic biopsies are often diagnostic. When abnormalities involve layers two and three, different diseases can be suspected, including Helicobacter pylori infection and lymphoma; in this case large-particle biopsy should be considered. When abnormalities involve layer four, malignancy should be strongly suspected even if standard or large-particle biopsies are negative. Endosonography, always in combination with fine-needle or guillotine-needle biopsy, should be able to rule out malignancies and to select the most appropriate treatment for each patient. © Georg Thieme Verlag

Endosonography in gastric lymphoma and large gastric folds

To establish a correct preoperative differential diagnosis between gastric lymphoma and cancer is essential but can be difficult as endoscopic biopsies can sometimes provide a low diagnostic yield. By EUS, infiltrative carcinoma tends to show a vertical growth in the gastric wall, while lymphoma tends to show mainly a horizontal extension. EUS provides an accurate staging of gastric lymphoma, showing the exact level of infiltration and the presence of perigastric lymph nodes, thus the physician can obtain an accurate prognosis for each patient and select the best form of treatment accordingly. The response to chemoradiotherapy can also be investigated very accurately by EUS. Large gastric folds are seen in a great number of benign and malignant conditions. Diagnosis represents a clinical challenge because etiology may be extremely varied and standard biopsies are often inconclusive. Different diseases show different levels of infiltration of the gastric wall, thus a characteristic echo-pattern helps for the differential diagnosis. Endosonography, used always in combination with biopsy, allows to rule out malignancies and to select the most appropriate treatment for each patient (medical or surgical). (C) 2000 Elsevier Science Ireland Ltd