Haifa District
HAR-DoReMi: Optimizing Data Mixture for Self-Supervised Human Activity Recognition Across Heterogeneous IMU Datasets
Ban, Lulu, Zhu, Tao, Lu, Xiangqing, Qiu, Qi, Han, Wenyong, Li, Shuangjian, Chen, Liming, Wang, Kevin I-Kai, Nie, Mingxing, Wan, Yaping
Cross-dataset Human Activity Recognition (HAR) suffers from limited model generalization, hindering its practical deployment. To address this critical challenge, inspired by the success of DoReMi in Large Language Models (LLMs), we introduce a data mixture optimization strategy for pre-training HAR models, aiming to improve the recognition performance across heterogeneous datasets. However, directly applying DoReMi to the HAR field encounters new challenges due to the continuous, multi-channel and intrinsic heterogeneous characteristics of IMU sensor data. To overcome these limitations, we propose a novel framework HAR-DoReMi, which introduces a masked reconstruction task based on Mean Squared Error (MSE) loss. By raplacing the discrete language sequence prediction task, which relies on the Negative Log-Likelihood (NLL) loss, in the original DoReMi framework, the proposed framework is inherently more appropriate for handling the continuous and multi-channel characteristics of IMU data. In addition, HAR-DoReMi integrates the Mahony fusion algorithm into the self-supervised HAR pre-training, aiming to mitigate the heterogeneity of varying sensor orientation. This is achieved by estimating the sensor orientation within each dataset and facilitating alignment with a unified coordinate system, thereby improving the cross-dataset generalization ability of the HAR model. Experimental evaluation on multiple cross-dataset HAR transfer tasks demonstrates that HAR-DoReMi improves the accuracy by an average of 6.51%, compared to the current state-of-the-art method with only approximately 30% to 50% of the data usage. These results confirm the effectiveness of HAR-DoReMi in improving the generalization and data efficiency of pre-training HAR models, underscoring its significant potential to facilitate the practical deployment of HAR technology.
Fast and Accurate Least-Mean-Squares Solvers
Alaa Maalouf, Ibrahim Jubran, Dan Feldman
Least-mean squares (LMS) solvers such as Linear / Ridge / Lasso-Regression, SVD and Elastic-Net not only solve fundamental machine learning problems, but are also the building blocks in a variety of other methods, such as decision trees and matrix factorizations. We suggest an algorithm that gets a finite set of n d-dimensional real vectors and returns a weighted subset of d + 1 vectors whose sum is exactly the same. The proof in Caratheodory's Theorem (1907) computes such a subset in O(n
Google's biotech company pulls out of Israel but says Gaza war not the reason
Google's health and data company, Verily, is closing its operations in Israel three years after opening a research and development center in the country. Verily staff in Israel are expected to leave by the third quarter of 2024. The company cited an effort to refocus its strategy on core products and projects as the reason for the closure. "As part of our ongoing review of business needs, Verily has made the difficult decision to begin the process to close its R&D center in Israel located in both Haifa and Tel Aviv," a spokesperson for Verily said. "This decision is in keeping with our strategy as we continue to streamline our overall company operations."
Yemen's Houthis claim joint raid on Israeli ships with Iraqi militia
Yemen's Houthis have claimed carrying out a joint military operation with an Iranian-backed Iraqi militia, known as the Islamic Resistance in Iraq, to target four vessels in Israel's Haifa port. Houthi military spokesman Yahya Saree said in a televised statement on Sunday that the group fired drones at two cement tankers and two cargo ships at the port a day prior over noncompliance with a ban on entering "ports of occupied Palestine". Saree added that the group had also targeted a Shorthorn Express ship in the Mediterranean Sea using drones, and both operations "successfully achieved their goals". Israel's Channel 12 reported an explosion occurred in Haifa at dawn after an air defence missile was launched towards the sea without activating the sirens. Israel's military did not comment on the Houthi claim, but stated in a post on X that it had shot down a drone approaching the country overnight from the east.
Israel ready for 'all-out war' in Lebanon
Israel is ready for an "all-out war" in Lebanon and has plans approved for an offensive targeting Hezbollah, officials have said. The claims from Israel's foreign minister and military late on Tuesday followed Hezbollah's release of threatening drone footage. The climbing tension conflicts with United States efforts to avert an escalation amid months of low-level hostilities across the Israel-Lebanon border. The nine-minute drone footage of the Israeli port city of Haifa filmed in daytime, showed civilian and military areas, including malls and residential quarters, in addition to a weapons manufacturing complex and missile defence batteries. Israel's Foreign Minister Israel Katz responded vehemently in a post on X, calling out Hezbollah chief Hassan Nasrallah for boasting about filming the ports of Haifa, which are operated by foreign companies from China and India.
Bandit Convex Optimization: Towards Tight Bounds Kfir Y. Levy Technion--Israel Institute of Technology Technion--Israel Institute of Technology Haifa 32000, Israel
Bandit Convex Optimization (BCO) is a fundamental framework for decision making under uncertainty, which generalizes many problems from the realm of online and statistical learning. While the special case of linear cost functions is well understood, a gap on the attainable regret for BCO with nonlinear losses remains an important open question. In this paper we take a step towards understanding the best attainable regret bounds for BCO: we give an efficient and near-optimal regret algorithm for BCO with strongly-convex and smooth loss functions. In contrast to previous works on BCO that use time invariant exploration schemes, our method employs an exploration scheme that shrinks with time.
Online Learning for Adversaries with Memory: Price of Past Mistakes Princeton University Haifa, Israel
The framework of online learning with memory naturally captures learning problems with temporal effects, and was previously studied for the experts setting. In this work we extend the notion of learning with memory to the general Online Convex Optimization (OCO) framework, and present two algorithms that attain low regret. The first algorithm applies to Lipschitz continuous loss functions, obtaining optimal regret bounds for both convex and strongly convex losses. The second algorithm attains the optimal regret bounds and applies more broadly to convex losses without requiring Lipschitz continuity, yet is more complicated to implement. We complement the theoretical results with two applications: statistical arbitrage in finance, and multi-step ahead prediction in statistics.
Exploring Values in Museum Artifacts in the SPICE project: a Preliminary Study
Kadastik, Nele, Pederson, Thomas A., Bruni, Luis Emilio, Damiano, Rossana, Lieto, Antonio, Striani, Manuel, Kuflik, Tsvi, Wecker, Alan
This document describes the rationale, the implementation and a preliminary evaluation of a semantic reasoning tool developed in the EU H2020 SPICE project to enhance the diversity of perspectives experienced by museum visitors. The tool, called DEGARI 2.0 for values, relies on the commonsense reasoning framework TCL, and exploits an ontological model formalizingthe Haidt's theory of moral values to associate museum items with combined values and emotions. Within a museum exhibition, this tool can suggest cultural items that are associated not only with the values of already experienced or preferred objects, but also with novel items with different value stances, opening the visit experience to more inclusive interpretations of cultural content. The system has been preliminarily tested, in the context of the SPICE project, on the collection of the Hecht Museum of Haifa.