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Hilbert curves for efficient exploratory landscape analysis neighbourhood sampling

arXiv.org Artificial Intelligence

Landscape analysis aims to characterise optimisation problems based on their objective (or fitness) function landscape properties. The problem search space is typically sampled, and various landscape features are estimated based on the samples. One particularly salient set of features is information content, which requires the samples to be sequences of neighbouring solutions, such that the local relationships between consecutive sample points are preserved. Generating such spatially correlated samples that also provide good search space coverage is challenging. It is therefore common to first obtain an unordered sample with good search space coverage, and then apply an ordering algorithm such as the nearest neighbour to minimise the distance between consecutive points in the sample. However, the nearest neighbour algorithm becomes computationally prohibitive in higher dimensions, thus there is a need for more efficient alternatives. In this study, Hilbert space-filling curves are proposed as a method to efficiently obtain high-quality ordered samples. Hilbert curves are a special case of fractal curves, and guarantee uniform coverage of a bounded search space while providing a spatially correlated sample. We study the effectiveness of Hilbert curves as samplers, and discover that they are capable of extracting salient features at a fraction of the computational cost compared to Latin hypercube sampling with post-factum ordering. Further, we investigate the use of Hilbert curves as an ordering strategy, and find that they order the sample significantly faster than the nearest neighbour ordering, without sacrificing the saliency of the extracted features.


OpenUAS: Embeddings of Cities in Japan with Anchor Data for Cross-city Analysis of Area Usage Patterns

arXiv.org Artificial Intelligence

We publicly release OpenUAS, a dataset of area embeddings based on urban usage patterns, including embeddings for over 1.3 million 50-meter square meshes covering a total area of 3,300 square kilometers. This dataset is valuable for analyzing area functions in fields such as market analysis, urban planning, transportation infrastructure, and infection prediction. It captures the characteristics of each area in the city, such as office districts and residential areas, by employing an area embedding technique that utilizes location information typically obtained by GPS. Numerous area embedding techniques have been proposed, and while the public release of such embedding datasets is technically feasible, it has not been realized. One of the obstacles has been the integration of data from different cities and periods into a unified space without sharing raw location data. We address this issue by developing an anchoring method that establishes anchors within a shared embedding space. We publicly release this anchor dataset along with area embedding datasets from several periods in eight major Japanese cities. This dataset allows users to analyze urban usage patterns in Japanese cities and embed their urban dataset into the same embedding space using the anchoring method. Our key contributions include the development of the anchoring method, releasing area embedding datasets for Japanese cities, and providing tools for effective data utilization.


Coverage Path Planning For Minimizing Expected Time to Search For an Object With Continuous Sensing

arXiv.org Artificial Intelligence

In this paper, we present several results of both theoretical as well as practical interests. First, we propose the quota lawn mowing problem, an extension of the classic lawn mowing problem in computational geometry, as follows: given a quota of coverage, compute the shortest lawn mowing route to achieve said quota. We give constant-factor approximations for the quota lawn mowing problem. Second, we investigate the expected detection time minimization problem in geometric coverage path planning with local, continuous sensory information. We provide the first approximation algorithm with provable error bounds with pseudopolynomial running time. Our ideas also extend to another search mechanism, namely visibility-based search, which is related to the watchman route problem. We complement our theoretical analysis with some simple but effective heuristics for finding an object in minimum expected time, on which we provide simulation results.


Co-designing an AI Impact Assessment Report Template with AI Practitioners and AI Compliance Experts

arXiv.org Artificial Intelligence

In the evolving landscape of AI regulation, it is crucial for companies to conduct impact assessments and document their compliance through comprehensive reports. However, current reports lack grounding in regulations and often focus on specific aspects like privacy in relation to AI systems, without addressing the real-world uses of these systems. Moreover, there is no systematic effort to design and evaluate these reports with both AI practitioners and AI compliance experts. To address this gap, we conducted an iterative co-design process with 14 AI practitioners and 6 AI compliance experts and proposed a template for impact assessment reports grounded in the EU AI Act, NIST's AI Risk Management Framework, and ISO 42001 AI Management System. We evaluated the template by producing an impact assessment report for an AI-based meeting companion at a major tech company. A user study with 8 AI practitioners from the same company and 5 AI compliance experts from industry and academia revealed that our template effectively provides necessary information for impact assessments and documents the broad impacts of AI systems. Participants envisioned using the template not only at the pre-deployment stage for compliance but also as a tool to guide the design stage of AI uses.


In-Context Example Selection via Similarity Search Improves Low-Resource Machine Translation

arXiv.org Artificial Intelligence

The ability of generative large language models (LLMs) to perform in-context learning has given rise to a large body of research into how best to prompt models for various natural language processing tasks. In this paper, we focus on machine translation (MT), a task that has been shown to benefit from in-context translation examples. However no systematic studies have been published on how best to select examples, and mixed results have been reported on the usefulness of similarity-based selection over random selection. We provide a study covering multiple LLMs and multiple in-context example retrieval strategies, comparing multilingual sentence embeddings. We cover several language directions, representing different levels of language resourcedness (English into French, German, Swahili and Wolof). Contrarily to previously published results, we find that sentence embedding similarity can improve MT, especially for low-resource language directions, and discuss the balance between selection pool diversity and quality. We also highlight potential problems with the evaluation of LLM-based MT and suggest a more appropriate evaluation protocol, adapting the COMET metric to the evaluation of LLMs. Code and outputs are freely available at https://github.com/ArmelRandy/ICL-MT.


Efficient Patient Fine-Tuned Seizure Detection with a Tensor Kernel Machine

arXiv.org Artificial Intelligence

Recent developments in wearable devices have made accurate and efficient seizure detection more important than ever. A challenge in seizure detection is that patient-specific models typically outperform patient-independent models. However, in a wearable device one typically starts with a patient-independent model, until such patient-specific data is available. To avoid having to construct a new classifier with this data, as required in conventional kernel machines, we propose a transfer learning approach with a tensor kernel machine. This method learns the primal weights in a compressed form using the canonical polyadic decomposition, making it possible to efficiently update the weights of the patient-independent model with patient-specific data. The results show that this patient fine-tuned model reaches as high a performance as a patient-specific SVM model with a model size that is twice as small as the patient-specific model and ten times as small as the patient-independent model.


Sudan's military chief survives a drone strike on army base

Al Jazeera

The head of the Sudanese Armed Forces, General Abdel Fattah al-Burhan survived a drone strike on the Gebeit army base while attending a graduation ceremony. Five people were killed in the strike.


Sudan's army leader rejects new round of talks after drone strike

Al Jazeera

Sudan's army leader, General Abdel Fattah al-Burhan, says the military will not join talks next month in Switzerland aimed at ending more than a year of fighting with the paramilitary Rapid Support Forces (RSF). Al-Burhan made the statement on Wednesday, shortly after the military said he survived a drone strike on a military graduation at the Gibeit army base in eastern Sudan that killed at least five people. "We will not retreat, we will not surrender and we will not negotiate," al-Burhan told troops. "We are not scared of drones," he said at the Gibeit base, which is about 100km (62 miles) southwest of Port Sudan, where the army-aligned government fled after war broke out with the RSF in April last year. The fighting has created the world's largest displacement crisis and killed at least 15,500 people, according to United Nations estimates. Video of the drone attack, verified by the Reuters news agency, showed soldiers marching in a graduation ceremony before a whirring sound can be heard.


Sudan's military leader survives drone strikes - army

BBC News

Previous talks to end the conflict, which has created the world's largest humanitarian crisis, have failed as both sides have refused to honour their commitments. More than 10 million people have fled their homes since the former allies fell out over an internationally backed political plan to move towards civilian rule. The Jabait army base is about 100km (62 miles) from Port Sudan, the military's de facto capital and where Gen Burhan is based. Video footage being shared from those attending the ceremony on Wednesday morning shows military graduates marching in ceremonial dress before the sound of a strike. "The only party that is hostile to the Sudanese people and targeting the Sudanese people is the rebel Rapid Support Forces," Gen Abdallah told the BBC.


A Culturally-Aware Tool for Crowdworkers: Leveraging Chronemics to Support Diverse Work Styles

arXiv.org Artificial Intelligence

This issue usually stems from the assumption that crowdworkers are a homogeneous group [56], neglecting their diverse cultural backgrounds [90]. Moreover, a notable trend in design has emerged advocating for minimizing cultural impact in work interfaces, aiming for global uniformity in their design rather than customizing these systems to accommodate cultural nuances [133, 134, 193]. Consequently, many work interfaces have strived for uniform standards, and have ignored worker diversity [76, 84, 88]. However, interfaces often reflect the cultural biases of their designers [18], inadvertently embedding their cultural norms [146, 150, 177]. This can lead to designs that unintentionally require "outside workers" to adapt or modify their behaviors [126, 177], potentially hindering their success and effectiveness in their jobs [24, 60, 64, 85]. A solution can be to create culturally aware tools for crowdworkers, yet research into integrating culture theory into such designs remains limited [108, 118, 163]. Further research is crucial to assess these systems' effectiveness and their potential benefits for crowdworkers from varied cultural backgrounds. To address this knowledge gap, we focus on designing a tool that aims to enhance crowdworkers' experiences by incorporating cultural considerations.