Publikationer från Linköpings universitet
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A Conceptual Comparison of Hydraulic and Electric Actuation Systems for a Generic Fighter Aircraft
No full textThis paper presents a methodology for evaluating different flight control actuation system architectures in the early conceptual design phase. In particular, this paper shows how hydraulic and electric actuators can be modeled even if very little is known about the aircraft design or requirements while still including the most dominant static and dynamic characteristics. Singular Value Decomposition is used to estimate model parameters and actuator characteristics from industrial data. This is a quick way to estimate what is needed with little input. The purpose of the models is to predict the power consumption, cooling needs, weight, and size. This is performed by integrating the actuator models in a dynamic simulation framework that also includes a flight simulator and surrounding systems. The results from subsystem studies support the aircraft design process, where actuator characteristics affect the engine performance and aircraft sizing. The methodology is applied to a generic fighter by comparing hydraulic and electric actuation system architectures. Besides providing a generic approach to the actuator modeling, the parameters that affect both the static and dynamic characteristics of an electromechanical and electrohydrostatic actuator are estimated with reasonably good accuracy with only four design parameters as input.Funding Agencies|VINNOVA; [2019-02772]; [2020-00497]</p
Unexplored avenues: a narrative review of cognition and mood in postmenopausal African women with female genital circumcision/mutilation/cutting
No full textRecent ageing research has projected the lifespan and proportion of postmenopausal women living in low- and middle-income countries to substantially increase over the years, especially on the African continent. An important subgroup within the African postmenopausal population is those with female genital circumcision/mutilation/cutting (FGC). Practised across 31 African nations, FGC holds cultural significance as it is deemed essential to marriage and successful womanhood. Perhaps because of this, most FGC studies have primarily focused on women's reproductive functioning and their mood experiences. These studies also usually exclude postmenopausal women from their cohorts. Consequently, cognition and age-related cognitive decline and preservation remain understudied. Therefore, we investigated what is known about mood and cognition in local and immigrant postmenopausal African women with FGC. To do this, we carried out a narrative review searching PubMed, PsycInfo, and Google Scholar databases. Boolean combinations of keywords related to FGC, cognition, ageing, and mood were used, with a focus on cognition and ageing-related terms. Only studies published in English, those that recruited African women with FGC aged 50 years and older, and those that investigated cognitive and/or mood-related experiences were included. Ten studies were found; these included quantitative, qualitative, and case reports. The age range of cohorts across included studies was 13-90 years; women who were likely postmenopausal formed a minority within the cohorts (4.5%-25%). There were no studies assessing memory or cognition beyond those looking at FGC-related memories, which were vivid, especially if women had type III FGC (Pharaonic) or were older at the time of FGC. Although most of these women reported experiencing negative emotions concerning FGC, quantitative reports showed that only a minority of women experienced post-traumatic stress disorder, anxiety, or depression. Thus, there remains an urgent need to bring this understudied group into ageing and dementia research. Future research should adopt mixed-methods with culturally sensitive methodologies to investigate the lived experience of ageing as well as cognitive changes. A holistic understanding of ageing women from the Horn of Africa's experiences and needs will support an improvement in the quality of care delivered to this cohort in both local and immigrant contexts.Funding Agencies|Wilfred and Joyce Posluns Chair in Women's Brain Health and Aging from the Posluns Family Foundation; Canadian Institutes of Health Research (CIHR); Ontario Brain Institute; Alzheimer Society of Canada [WJP-150643]; Canadian Consortium on Neurodegeneration in Aging (CCNA) Phase II [CCNA 049-04]; CIHR [CNA 163902]; Jacqueline Ford Gender and Health Fund</p
Woven, In-Air, Textile Actuators by Conjugated Polymers and Solid-State Electrolyte Tape Yarns
No full textSoft actuators are necessary for the development of soft robotics. While advances have been made in creating artificial means of motion with compliant materials, challenges remain. Within the area of electromechanically active polymers, forces are often small and limited to wet electrolyte conditions. Herein, textile logics and processes are employed to demonstrate woven, in-air operating, freestanding, soft textile actuators which can be electrically controlled. In-air actuating trilayer tape yarn consisting of poly(3,4ethylenedioxythiophene): polystyrenesulfonate layers and an ionogel are developed. The former acts as polymeric electroactive electrodes and the latter as a solid-state electrolyte, providing ions for the actuation. Weaving is used for creating bending fabrics, possible to post-process like any fabric. By weaving, actuator tape yarns are assembled in parallel to upscale the total output force, or alternated with non-actuating yarns to make passive and active areas. The weaving method also allows for additional yarn functionalities to be incorporated, e.g., to make conductive pathways, enabling multi-actuation areas, and individual electrical control. Additionally, tape yarns are arranged to create textile structures with both actuation and sensing. As a proof-of-concept, the developed fabric actuators enable novel wearable robotic devices for future applications that are inherently soft, lightweight, and multifunctional.Funding Agencies|Stiftelsen Promobilia</p
To be or not to be satisfied in your romantic relationship: evaluating the reliability and validity of the Valentine scale
No full textAn intimate partner relationship is one of the most significant life goals for humans. Romantic relationships can promote healthy behavior and buffer against the development of psychiatric disorders. However, reliable and valid measures of relationship satisfaction are lacking. The Valentine scale is a freely available brief measure of relationship satisfaction (https://osf.io/fb72s), intended to provide an easily interpretable index of relationship satisfaction. Across two studies, we evaluated the reliability, validity, and factor structure of the Valentine scale. Study One (n = 851) explored the factor structure of the Valentine scale, assessed its test-retest reliability, and criterion-related validity. Study Two (n = 527) confirmed the factor structure of the Valentine scale, explored its measurement invariance, and further evaluated criterion-related validity. The results supported a unidimensional structure of the Valentine scale. Furthermore, the Valentine scale exhibited good internal reliability (Cronbach's alpha = .75 and .81 in Study One and Two, respectively), high test-retest reliability (ICC3 = .80 at a two-week follow-up in Study One), and appropriate criterion-related validity demonstrating positive correlations with other measures of relationship satisfaction and positive affect, as well as and negative correlations with measures of psychopathology. Together, these findings provide good support for the usage of the Valentine scale to quantify relationship satisfaction
A survey on Swedish maritime pilots’ trust, training, understanding, and use of the portable pilot unit’s predictor automation
No full textTechnological advances such as electronic charts and course prediction systems provide invaluable support to navigation officers and maritime pilots in navigating confined waters. However, recent maritime accidents have been attributed to operators lacking a clear understanding of how the automation works and how to use it, leading to both misuse and disuse. Two concerns emerge: inadequate training and poor automation design, making it difficult and complex to use. To investigate challenges related to understanding, use, and trust in automation, we surveyed Swedish maritime pilots to investigate their experiences with the course predictor automation tool on their portable pilot units. This technology predicts ship trajectories and is commonly used in modern bridge systems. This paper contributes empirical evidence on how maritime pilots trust the predictor currently used, providing insight into their perceptions and experiences of training, level of understanding, and patterns of usage. The results of 69 respondents revealed limited formal training in the predictor, with knowledge acquired primarily from self-learning and practical experience. Although pilots value the predictor and use it frequently, they struggle with sensor error detection and understanding how it works. The trust in the predictor was inversely correlated with age and experience, with lower age and experience associated with higher trust, more frequent use, greater perceived importance, better understanding, and fewer unexplained behaviours encountered. Based on these findings, recommendations are proposed to improve predictor training and improve its transparency through design.Funding Agencies|Linkoping University; Swedish Maritime Administration [TRV 2017/64269]; Swedish Air Navigation Service Provider; Swedish Transport AdministrationRESKIL
The health paradoxes of social media influencers
No full textThis paper describes and discusses social media influencers’ health-related costs of keeping traction as influencers. The paper is based on interviews and social media posts. Four paradoxes highlight the social media influencers’ contradictory circumstances: (1) the social media influencer’s well-being is situated between not being dependent on income and earning the income to avoid monetary stress; (2) well-being becomes associated with playing a role, while authenticity is crucial for the influencer; (3) the premises of being a successful social media influencer is what creates their despair; and (4) being exposed as a healthy role model risks harming the well-being of the social media influencer. The paper takes a unique perspective on social media influencers, focusing on their well-being rather than their promotional power. The paper helps to create socially sustainable conditions for influencers, while it adds to theory through outlining influencers’ paradoxical conditions.Funding agencies: Open access funding provided by Linnaeus University.</p
Edge modes in strongly nonlinear saturable SSH photonic lattices: Tracing a bulk-edge correspondence through instabilities and bifurcations
No full textPhotonic lattices with a saturable nonlinear response generally exhibit a second linear regime at high light intensities. Here, we perform a detailed numerical analysis of nonlinear continuations of the topological edge mode of a Su-Schrieffer-Heeger (SSH) chain, following the family of exact nonlinear stationary solutions through instabilities and bifurcations from the low-intensity to the high-intensity linear limit. The properties of the nonlinear edge modes define several regimes corresponding to qualitatively different dynamics for edge excitations. For each of these nonlinear regimes we numerically calculate the evolution of two commonly used indicators of nontrivial bulk topology: the mean field displacement and the Zak phase obtained from projector matrices. Thus, we determine the extent to which one may establish an approximate bulk-edge correspondence, characterized by dynamically stable nonlinear edge modes and well defined approximate Zak phases, in the full nonlinear regime of the saturable lattice.Funding Agencies|Millennium Science Initiative Program [ICN17_012]; ANID FONDECYT [1231313]; Ministry of Science, Technological Development and Innovation of the Republic of Serbia [451-03-66/2024-03/200017]</p
Navigating unhinged paradoxes : an interdisciplinary roadmap for energy efficiency in data centers
No full textInterdisciplinary teams skilled in Aristotle’s three knowledge forms, phronesis, episteme, techne, are essential for dealing with complex challenges in future. As sectors transition to new concepts, risks exist for unhinged paradoxes, i.e., unforeseen consequences. This is particularly relevant for industries with complex infrastructures, such as data centers (DCs). This paper presents a conceptual roadmap consisting of four interconnected phases for integrating energy efficiency concepts in DCs, with a focus on avoiding unhinged paradoxes. The knowledge creation process during the roadmapping process underscores the importance from (1) the acknowledgement of an external threat, (2) inclusion of an interdisciplinary team, and (3) regular project meetings to facilitate a collaborative and interdisciplinary environment. Additionally, the insights gained from this research extend to sectors beyond DCs and can be applied to other industries working towards increased energy efficiency. Funding Agencies|Energimyndigheten [50227-1]</p
60-day mortality and the role of SARS-CoV-2 in hospital admissions of immunocompromised patients during later Omicron period: a population-based study in Sweden
No full textBackgroundReal-world data on hospitalised SARS-CoV-2-positive patients are important for post-pandemic preventive measures.ObjectivesThis study aims to explore 60-day mortality of immunocompromised patients hospitalised in later Omicron period, accounting for the relevance of COVID-19 for hospital care.MethodsA retrospective population-based cohort study in & Ouml;sterg & ouml;tland County, Sweden, included all adult patients with a positive SARS-CoV-2 PCR test within 3 weeks of hospital admission. Clinical data including functional level (combined assessment of frailty and performance status), and COVID-19's impact on hospital care were collected from medical records. An adjusted binary logistic regression model was applied for the main outcome of 60-day COVID-19-related mortality, with immunosuppression as the main exposure.Results1128 hospitalised SARS-CoV-2-positive patients were included in the analysis whereof 12.9% were immunocompromised. Hospital admission due to COVID-19 was significantly more common among immunocompromised than non-immunocompromised (71.9% vs 49.5%), and 60-day COVID-19 mortality was 10.5% and 8.0% (p = 0.41), respectively. The median age of patients hospitalised due to COVID-19 was 78 years, with most having low/very low functional levels and &gt;= 3 comorbidities. Adjusted for possible confounders, immunosuppression showed a significantly increased risk of 60-day COVID-19-related mortality (OR 2.41, 95% CI 1.06-5.47, p = 0.04).ConclusionA majority of COVID-19-related hospitalisations during later Omicron period in a high immunity population, involved people over 70 years with low/very low functional levels and multiple comorbidities. Immunocompromised patients had a 2.5 times higher risk of 60-day COVID-19-related mortality. These findings underscore the need for targeted preventive measures in vulnerable elderly and immunocompromised populations to mitigate COVID-19-related hospitalisations and deaths.Funding Agencies|Swedish Research Council [VR 2021-05608]; Region Ostergotland [ALF-936190]; Research Council of Southeast Sweden [FORSS-940915]; Swedish Heart-Lung Foundation [20220238]</p
Uncomplicated Diverticulosis Is Not Associated With Abdominal Pain or Abnormal Bowel Habit-A Population-Based Swedish Cohort Study
No full textBackgroundWhether uncomplicated diverticulosis gives rise to symptoms is controversial. Diary-based studies of abdominal pain and stool habits in general populations are scarce, and we therefore investigated symptom patterns in diverticulosis from prospectively collected symptom diaries in a random sample of the general population who completed a research colonoscopy.MethodsIn the Swedish population-based colonoscopy (PopCol) study, 745 individuals from the general population underwent a colonoscopy of which 130 had diverticulosis, and none had diverticulitis. Seven-day symptom diaries were completed by 258 participants (age 54, women 64%) of which 50 had diverticulosis. The frequency and location of abdominal pain, bowel habit and other gastrointestinal symptoms were compared between individuals with and without diverticulosis using logistic regression.Key ResultsDiverticulosis was not associated with abdominal pain (OR 1.24, CI 0.61-2.55) or left lower quadrant (LLQ) abdominal pain (OR 1.59, CI 0.73-3.49). Pain duration and severity were not associated with diverticulosis. When individuals with diverticulosis had pain, it was more often in the LLQ (OR 2.45, CI 1.02-5.86) compared with those without diverticulosis. Diverticulosis was not linked to altered bowel habits. Irritable bowel syndrome prevalence was 16% in the diverticulosis group and 19% in the non-diverticulosis group.Conclusions and InferencesParticipants with diverticulosis did not report more abdominal pain or more LLQ abdominal pain than participants without diverticulosis. Bowel habit was not abnormal in diverticulosis. Our results do not support that uncomplicated diverticulosis cause symptoms in individuals without a history of acute diverticulitis.Funding Agencies|Stiftelsen Professor Nanna Svartz Fond</p