Agder Research

Nonlinear friction has long been, and continues to be, one of the major challenges for precision motion control systems. A linear asymptotic observer of the motion state variables with nonlinear friction uses a dedicated state-space representation of the dynamic friction force (including pre-sliding) (Ruderman, 2023b), which is robust to the noisy input signals. The observer implements the reduced-order Luenberger observation law, while assuming the output displacement is the only available measurement. The latter is relevant for multiple motion control applications with use of encoder-type sensors. The uniform asymptotic stability and convergence analysis of the proposed observer are elaborated in the present work by using the Lyapunov function-based stability criterion by Ignatyev and imposing parametric constraints on the time-dependent eigenvalues of the system matrix to be always negative real. A design procedure for assigning a dominant, and thus slowest, real pole of the observer is proposed. Explanative numerical examples accompany the developed analysis. In addition, a thorough experimental evaluation is given for the proposed observer-based friction compensation which is performed for positioning and tracking tasks. The observer-based compensation, which can serve as a plug-in to a standard feedback controller, extends a PID feedback control that is optimally tuned for disturbance suppression. The experimental results are compared with and without the plugged-in observer-based compensator.

With the emergence of generative artificial intelligence, dialogue systems like chatbots are redefining traditional concepts of authorship and impacting critical aspects of writing. In educational contexts, previous research has pointed out new opportunities associated with using chatbots for writing instruction and support. This study involved 108 students across 10 classes in Norwegian K-12 education, examining how they employed educational chatbots as a support tool in L1 writing assignments. Through an inductive, data-driven thematic analysis of 895 student prompts, five recurring patterns emerged: information requests, structural guidance, example requests, content creation, feedback on text, and follow-up clarification. Aggregated results show that information requests were the most common pattern, particularly among younger students, whereas content creation and feedback on text were more prevalent among secondary and upper secondary students. Illustrative examples from the conversations revealed that generative AI extensively produced content on student’s behalf, even when students primarily sought scaffolding. The study proposes that effective scaffolding of writing through educational chatbots requires not only refining students' prompting strategies but also enhancing system designs that better support pedagogical use of generative AI.

The high degree of digitalization in Scandinavian countries has led to challenges for those who find themselves digitally excluded, facing several barriers to participation in society. Many may receive help from “warm experts”, i.e. family members or friends, but that is not possible for all. Different groups of frontline government workers may also act as helpers, even if they do not have assistance with digital public services as a core part of their remit. In Norway, health personnel often care for citizens in their home settings and may frequently be asked to help with digital challenges. This study aims to explore the nature of the work that nurses do in helping citizens with digital challenges, and challenges that they face in doing this. This explorative study is based on a survey of 3.044 nurses working in the Norwegian municipal sector. The survey constitutes a combination of a qualitative (open ended questions) and quantitative approach (closed questions), The open-ended questions were thematically analyzed and the close questions were used for descriptive statistics. The findings show that nurses do considerable invisible work in helping patients with digital technology. They frequently help with both basic hardware and software challenges, as well as with specific services, some of which are related to health. Many do this driven by their professional ethos, believing this is vital to patients´ well-being. This takes time from other (core) tasks. They often worry about the help they provide and find themselves in a grey zone exacerbated by a lack of guidelines and support from peers and colleagues. The paper contributes to a deeper understanding of the invisible work nurses do due to digitalization of public services, and why they do this. Furthermore, the paper highlights the grey zone which many nurses must navigate, and the challenges they encounter. Although our findings are from a specific context, they may also apply to nurses and healthcare workers in other countries with high degrees of digitalization, and to some extent to other groups of frontline workers. Implications include better digital training but also more concrete guidelines for nurses on what to do when asked for digital help.

Healthcare professionals often face tension between caregiving values and systemic demands for efficiency and economic stability. While caregivers focus on patient well-being, hospital leaders must ensure resource and staff management-roles that can appear contradictory. This study explores how both caregivers and leaders in a large Norwegian hospital experience meaning in their work, aiming to identify shared ground for healthcare engagement. Drawing on Hartmut Rosa's resonance theory and Tatjana Schnell's research on meaning in life, we examine how professional experiences foster or hinder resonance-a mode of being characterized by mutual responsiveness and transformation. Twelve semi-structured interviews were conducted with nurses, doctors, and leaders using a guide informed by resonance theory. Data were analyzed thematically in a multidisciplinary team. Four themes emerged: (1) healthcare as a demanding yet meaningful profession, (2) organizational challenges, (3) patient relationships, and (4) teamwork and collegial support. Across roles, participants described systemic pressures that threaten meaningful engagement, but also highlighted moments of deep resonance-particularly in patient care, collaboration, and learning. Resonance and meaning are sustained when work aligns with moral purpose and supports relational and reflective engagement. Both caregivers and leaders seek meaning in their roles, often through shared values and relationships. These findings underscore the need for organizational structures that allow space for resonance, rather than accelerating alienation through excessive control and restructuring. Caring for meaning represents common ground for caregivers and leaders. A resonance-informed healthcare leadership might strengthen both staff well-being and quality of care.

This study explores Norwegian school mathematics teachers’ (grade 5–10) conceptions and teaching practices regarding mathematical modelling, as well as their views on its potentials and challenges, following the inclusion of mathematical modelling in the current Norwegian national curriculum — The Knowledge Promotion Reform (LK20). Ten mathematics teachers took part in semi-structured interviews. The findings show that most teachers conceptualise mathematical modelling in line with the curriculum, however, the teachers lack understanding from a cognitive perspective. The teachers focus on student engagement in their teaching practices that also emerged as a significant challenge, in addition to finding good tasks and guiding and evaluating students’ work.

Small data transmission (SDT) is a novel technique that allows IoT devices to transmit their payload data without a pre-allocated radio resource. However, unresolvable SDT collisions occur due to the unpredictability of IoT traffic. In this paper, we propose a semi-contention-free transmission scheme that combines dedicated time-slot allocation through hashing and random access with access control through a dueling deep Q-network. Focusing on uplink IoT traffic for SDT in a NOMA-enabled network with two clusters of devices, we implement the proposed scheme and demonstrate its effectiveness and performance with respect to throughput, latency, and energy consumption through extensive simulations.

Research on mitigating the negative effects of project work on project workers is scarce. This study analyzes the roles of psychological capital as an individual factor and coworker and family support as environmental factors in reducing the negative effects of project work. Building on the job demands-resources model and conservation of resources theory, the influence of these factors on the relationships between subjective stress, job burnout, and individual job performance is examined. The research model is empirically tested using data from a sample of 304 project workers. The results show that coworker and family support are positively associated with psychological capital. Additionally, psychological capital mediates the effects of social resources on subjective stress, which can lead to job burnout and poor work performance. Thus, coworker and family support and psychological capital can mitigate stress, job burnout, and their negative consequences. • How to reduce negative effects of project work on project workers? • Empirical study based on a sample of 304 project workers. • Coworker and family support are positively related to psychological capital. • Psychological capital mediates the effects of social resources on subjective stress. • Coworker-/family support and psychological capital mitigate stress and job burnout.