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Manifesto from Dagstuhl Perspectives Workshop 24352 - Conversational Agents:A Framework for Evaluation (CAFE)
Get PDFDuring the workshop, we deeply discussed what CONversational Information ACcess (CONIAC) is and its unique features, proposing a world model abstracting it, and defined the Conversational Agents Framework for Evaluation (CAFE) for the evaluation of CONIAC systems, consisting of six major components: 1) goals of the system's stakeholders, 2) user tasks to be studied in the evaluation, 3) aspects of the users carrying out the tasks, 4) evaluation criteria to be considered, 5) evaluation methodology to be applied, and 6) measures for the quantitative criteria chosen
COST CA20120 INTERACT Framework of Artificial Intelligence-Based Channel Modeling
Get PDFAccurate channel models are the prerequisite for communication-theoretic investigations as well as system design. Channel modeling generally relies on statistical and deterministic approaches. However, there are still significant limits for the traditional modeling methods in terms of accuracy, generalization ability, and computational complexity. The fundamental reason is that establishing a quantified and accurate mapping between the physical environment and channel characteristics becomes increasingly challenging for modern communication systems. Here, in the context of COST CA20120 Action, we evaluate and discuss the feasibility and implementation of using artificial intelligence (AI) for channel modeling, and explore where the future of this field lies. Firstly, we present a framework of AI-based channel modeling to characterize complex wireless channels. Then, we highlight in detail some major challenges and present the possible solutions: estimating the uncertainty of AI-based channel predictions; integrating prior knowledge of propagation to improve generalization capabilities; and interpretable AI for channel modeling. We present and discuss numerical results to showcase the capabilities of AI-based channel modeling.</p
ReLU integral probability metric and its applications
Get PDFWe propose a parametric integral probability metric (IPM) to measure the discrepancy between two probability measures. The proposed IPM leverages a specific parametric family of discriminators, such as single-node neural networks with ReLU activation, to effectively distinguish between distributions, making it applicable in high-dimensional settings. By optimizing over the parameters of the chosen discriminator class, the proposed IPM demonstrates that its estimators have good convergence rates and can serve as a surrogate for other IPMs that use smooth nonparametric discriminator classes. We present an efficient algorithm for practical computation, offering a simple implementation and requiring fewer hyperparameters. Furthermore, we explore its applications in various tasks, such as covariate balancing for causal inference and fair representation learning. Across such diverse applications, we demonstrate that the proposed IPM provides strong theoretical guarantees, and empirical experiments show that it achieves comparable or even superior performance to other methods
Degree is Important:On Evolving Homogeneous Boolean Functions
Get PDFBoolean functions with good cryptographic properties like high nonlinearity and algebraic degree play an important in the security of stream and block ciphers. Such functions may be designed, for instance, by algebraic constructions or metaheuristics. This paper investigates the use of Evolutionary Algorithms (EAs) to design homogeneous bent Boolean functions, i.e., functions that are maximally nonlinear and whose algebraic normal form contains only monomials of the same degree. In our work, we evaluate three genotype encodings and four fitness functions. Our results show that while EAs manage to find quadratic homogeneous bent functions (with the best method being a GA leveraging a restricted encoding), none of the approaches result in cubic homogeneous bent functions
The Stochastic Dynamic Postdisaster Inventory Allocation Problem with Trucks and UAVs
No full textHumanitarian logistics operations face increasing difficulties due to rising demands for aid in disaster areas. This paper investigates the dynamic allocation of scarce relief supplies across multiple affected districts over time. It introduces a novel stochastic dynamic postdisaster inventory allocation problem (SDPDIAP) with trucks and unmanned aerial vehicles (UAVs) delivering relief goods under uncertain supply and demand. The relevance of this humanitarian logistics problem lies in the importance of considering the intertemporal social impact of deliveries. We achieve this by considering social costs (transportation and deprivation costs) when allocating scarce supplies. Furthermore, we consider the inherent uncertainties of disaster areas and the potential use of cargo UAVs to enhance operational efficiency. This study proposes two anticipatory solution methods based on approximate dynamic programming, specifically decomposed linear value function approximation (DL-VFA) and neural network value function approximation (NN-VFA) to effectively manage uncertainties in the dynamic allocation process. We compare DL-VFA and NN-VFA with various state-of-the-art methods (e.g., exact reoptimization and proximal policy optimization) and results show a 6%–8% improvement compared with the best benchmarks. NN-VFA provides the best performance and captures nonlinearities in the problem, whereas DL-VFA shows excellent scalability against a minor performance loss. From a practical standpoint, the experiments reveal that consideration of social costs results in improved allocation of scarce supplies both across affected districts and over time. Finally, results show that deploying UAVs can play a crucial role in the allocation of relief goods, especially in the first stages after a disaster. The use of UAVs reduces transportation and deprivation costs together by 16%–20% and reduces maximum deprivation times by 19%–40% while maintaining similar levels of demand coverage, showcasing efficient and effective operations.</p
Talking About Barriers to Disease-Modifying Anti-Rheumatic Drugs:Content Analysis of Audio-Recorded Routine Clinical Visits of Patients with Rheumatoid Arthritis
Get PDFPurpose: Effective healthcare professional-patient communication is essential for medication adherence. Conversations about patient’s barriers to medication use, for example, could help to enhance adherence and consequently improve treatment outcomes. However, it is unclear whether and how barriers to medication use are discussed during routine rheumatology consultations. The aims of this study were to examine 1) the barriers and facilitators to medication use raised by patients during real-life rheumatology outpatient consultations, and whether the issue of medication (non)adherence was discussed (communication content); and 2) how rheumatologists responded to the barriers (communication process). Methods: A total of 134 audio-recordings of real-life outpatient rheumatology consultations were analysed. Barriers and facilitators for the current use of disease-modifying anti-rheumatic drugs were identified and categorized using a previously adapted Theoretical Domains Framework. The way rheumatologists responded to the barriers brought up by the patients was analysed using relevant parts of the Roter Interaction Analysis System. Results: In 58 of the 134 consultations, at least one barrier or facilitator to current medication use was brought up by the patient; in 31 out of 134 consultations, medication (non)adherence was addressed. Most facilitators were related to the quality of the needles, the use of an injection pen instead of a syringe, dose reduction because of low disease activity and timing of the medication. The majority of barriers were related to experiencing side effects and doubts about efficacy and resistance of (long-term use of) medication. Rheumatologists’ responses to barriers related to disease-modifying anti-rheumatic drugs were mostly a combination of instrumental (counselling) and affective (agreement) communication. Conclusion: Barriers to current disease-modifying anti-rheumatic drugs’ use raised by patients and discussed during routine rheumatology consultations were primarily related to side effects and concerns about the efficacy and long-term use. Continuous attention of these barriers and tailored responses to patients’ concerns are key to promote better adherence to treatment.</p
Stakeholder Perspectives on Built Environmental Factors to Support Stroke Rehabilitation and Return to Everyday Life
Get PDFBackground: The transition to undertaking rehabilitation in the home or local neighbourhood calls for an extensive understanding of which aspects of the built environment are important for people with stroke. Objective: This qualitative study aims to explore how home and local neighbourhood environments support or hinder rehabilitation for people who have had a stroke from the perspectives of various stakeholders. Methods: Through a purposive selection method, data were collected through semi-structured interviews with 16 stakeholders: people with stroke (n = 3), significant others (n = 3), healthcare professionals (n = 4), care managers (n = 3) and architects (n = 3). Content analysis was used to identify patterns and create themes. Findings: Sixteen stakeholders, including 12 women and 4 men aged 30–74, participated in this study. Our findings identify areas linked to the WHO age-friendly environment framework, which addresses environmental limitations relevant to stroke rehabilitation. The categories used and factors identified: (1) Outdoor environments: accessibility, safety and supportiveness. (2) Transport and mobility: accessible and reach central services. (3) Housing: adaptations, layout and accessibility. (4) Social participation: spaces that are varied and flexible. (5) Social inclusion and non-discrimination: shared decision-making. (6) Civic engagement and employment: supporting environments. (7) Communication and information: digital accessibility. (8) Community and health services: patient-centred approach and access to varied rehabilitation. Conclusion: This study brings together multiple perspectives from key stakeholders with experience within stroke care. By integrating insights, these findings highlight how built environmental factors in the home and local neighbourhood can support the transition to home-based rehabilitation, which can improve recovery and return to everyday life. In turn, this study contributes to the innovative development of home and neighbourhood environments to influence and support stroke rehabilitation. Linking the findings to the WHO framework increases our understanding of a supportive environment for people with stroke, but also for people with other long-term conditions. Patient or Public Contribution: This qualitative study is part of a comprehensive research project ‘(Built Environments to support rehabilitation for people with stroke, B-SURE)’, which aims to investigate how factors in the built environment influence stroke rehabilitation and to develop built environment solutions. B-SURE has a participatory methodology that essentially includes and involves the stakeholders in the multiple stages of the study and ensures an iterative and collaborative process.</p
Estimating tibial bone load during running using only inertial measurement units on the tibias and sternum:a Centre of Pressure approach
Get PDFInverse dynamics is a method to estimate joint forces and external moments needed for movement by analysing kinematics and ground reaction forces (GRF). In a bottom-up inverse dynamics analysis using a full-body inertial measurement unit (IMU) setup, the Centre of Pressure (CoP) is the only missing variable to complete the calculation. This study aimed to estimate the anteroposterior CoP from the tibia IMU orientation to calculate the sagittal ankle moment and tibial bone load (TBL) in rearfoot strikers running at 2.5, 3.1, and 3.6 m/s, using both tibia and the sternum IMU. This achieved strong correlations (≥0.90) for the CoP, sagittal ankle moment, and TBL compared with a marker/force plate reference. While the CoP estimate had fair accuracy, the sagittal ankle moment (rRMSE ≤ 12.9 %) and TBL (rRMSE ≤ 10.2 %) showed high accuracy. No significant differences were found between the IMU-only method and the reference for maximum ankle plantar flexion moment and TBL across all speeds. Future work should explore the multidimensional CoP, the inclusion of 3D GRF, and validation for non-rearfoot strike runners. These findings highlight the potential of using both tibia and the sternum IMU to monitor lower extremity forces and moments during running, independent of measurement location.</p
