| 1. |
- Alam, Moudud, 1976-, et al.
(author)
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Fitting conditional and simultaneous autoregressive spatial models in hglm
- 2015
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In: The R Journal. - 2073-4859. ; 7:2, s. 5-18
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Journal article (peer-reviewed)abstract
- We present a new version (> 2.0) of the hglm package for fitting hierarchical generalized linear models (HGLMs) with spatially correlated random effects. CAR() and SAR() families for conditional and simultaneous autoregressive random effects were implemented. Eigen decomposition of the matrix describing the spatial structure (e.g., the neighborhood matrix) was used to transform the CAR/SAR random effects into an independent, but eteroscedastic, Gaussian random effect. A linear predictor is fitted for the random effect variance to estimate the parameters in the CAR and SAR models. This gives a computationally efficient algorithm for moderately sized problems.
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| 2. |
- Alam, Md Moudud, 1976-
(author)
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Likelihood Prediction for Generalized Linear Mixed Models under Covariate Uncertainty
- 2014
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In: Communications in Statistics - Theory and Methods. - : Informa UK Limited. - 0361-0926 .- 1532-415X. ; 43:2, s. 219-234
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Journal article (peer-reviewed)abstract
- This article presents the techniques of likelihood prediction for the generalized linear mixed models. Methods of likelihood prediction are explained through a series of examples; from a classical one to more complicated ones. The examples show, in simple cases, that the likelihood prediction (LP) coincides with already known best frequentist practice such as the best linear unbiased predictor. This article outlines a way to deal with the covariate uncertainty while producing predictive inference. Using a Poisson errors-in-variable generalized linear model, it has been shown in certain cases that LP produces better results than already known methods.
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| 3. |
- Arzpeyma, Niloofar, et al.
(author)
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Model Development to Study Uncertainties in Electric Arc Furnace Plants to Improve Their Economic and Environmental Performance
- 2021
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In: Metals. - : MDPI. - 2075-4701. ; 11:6
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Journal article (peer-reviewed)abstract
- A statistical model is developed in order to simulate the melt composition in electric arc furnaces (EAFs) with respect to uncertainties in (1) scrap composition, (2) scrap weighing and (3) element distribution factors. The tramp element Cu and alloying element Cr are taken into account. The model enables simulations of a charge program as well as backwards estimations of the element concentrations and their variance in scrap. In the backwards calculation, the maximum likelihood method is solved by considering three cases corresponding to the involved uncertainties. It is shown that the model can estimate standard deviations for elements so that the real values lie within the estimated 95% confidence interval. Moreover, the results of the model application in each target product show that the estimated scrap composition results in a melt composition, which is in good agreement with the measured one. The model can be applied to increase our understanding of scrap chemical composition and lower the charged material cost and carbon footprint of the products.
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| 4. |
- Borg, Johan, et al.
(author)
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Experiences of Assistive Products and Home Care among Older Clients with and without Dementia in Sweden
- 2022
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In: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 19:19, s. 12350-12350
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Journal article (peer-reviewed)abstract
- The purpose was to compare selection, use and outcomes of assistive products among older home care clients with and without dementia in Sweden, and to explore the relations between the use of assistive products and perceptions of home care, loneliness and safety. Self-reported data from 89,811 home care clients aged 65 years or more, of whom 8.9% had dementia, were analysed using regression models. Excluding spectacles, 88.2% of them used assistive products. Respondents without dementia were more likely to use at least one assistive product but less likely to use assistive products for remembering. Respondents with dementia participated less in the selection of assistive products, used less assistive products, and benefited less from them. Users of assistive products were more likely to be anxious and bothered by loneliness, to feel unsafe at home with home care, to experience that their opinions and wishes regarding assistance were disregarded by home care personnel, and to be treated worse by home care personnel. The findings raise concerns about whether the needs for assistive products among home care clients with dementia are adequately provided for. They also indicate a need to strengthen a person-centred approach to providing home care to users of assistive products.
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| 5. |
- Johansson-Pajala, Rose-Marie, et al.
(author)
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Anxiety and loneliness among older people living in residential care facilities or receiving home care services in Sweden during the COVID-19 pandemic : a national cross-sectional study
- 2022
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In: BMC Geriatrics. - : Springer Science and Business Media LLC. - 1471-2318 .- 1471-2318. ; 22:1
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Journal article (peer-reviewed)abstract
- Background: Older people were subjected to significant restrictions on physical contacts with others during the COVID-19 pandemic. Social distancing impacts older people’s experiences of anxiety and loneliness. Despite a large body of research on the pandemic, there is little research on its effects on older people in residential care facilities (RCF) and in home care services (HCS), who are the frailest of the older population. We aimed to investigate the effect of the first wave of the COVID-19 pandemic in March-May 2020 on experiences of anxiety and loneliness among older people living in RCF or receiving HCS and the impact of the progression of the pandemic on these experiences.Methods: A retrospective cross-sectional design using data from the national user satisfaction survey (March − May 2020) by the Swedish National Board of Health and Welfare. Survey responses were retrieved from 27,872 older people in RCF (mean age 87 years) and 82,834 older people receiving HCS (mean age 84 years). Proportional-odds (cumulative logit) model was used to estimate the degree of association between dependent and independent variables.Results: Loneliness and anxiety were more prevalent among the older persons living in RCF (loneliness: 69%, anxiety: 63%) than those receiving HCS (53% and 47%, respectively). Proportional odds models revealed that among the RCF and HCS respondents, the cumulative odds ratio of experiencing higher degree of anxiety increased by 1.06% and 1.04%, respectively, and loneliness by 1.13% and 1.16%, respectively, for 1% increase in the COVID-19 infection rate. Poor self-rated health was the most influential factor for anxiety in both RCF and HCS. Living alone (with HCS) was the most influential factor affecting loneliness. Experiences of disrespect from staff were more strongly associated with anxiety and loneliness in RCF than in HCS.Conclusion: Older people in RCF or receiving HCS experienced increasing levels of anxiety and loneliness as the first wave of the pandemic progressed. Older people’ mental and social wellbeing should be recognized to a greater extent, such as by providing opportunities for social activities. Better preparedness for future similar events is needed, where restrictions on social interaction are balanced against the public health directives.
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| 6. |
- Johansson-Pajala, Rose-Marie, et al.
(author)
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Trust and easy access to home care staff are associated with older adults' sense of security : a Swedish longitudinal study
- 2024
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In: Scandinavian Journal of Public Health. - 1403-4948 .- 1651-1905. ; , s. 36830-
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Journal article (peer-reviewed)abstract
- AIM: Older adults are increasingly encouraged to continue living in their own homes with support from home care services. However, few studies have focused on older adults' safety in home care. This study explored associations between the sense of security and factors related to demographic characteristics and home care services.METHODS: The mixed longitudinal design was based on a retrospective national survey. The study population consisted of individuals in Sweden (aged 65+ years) granted home care services at any time between 2016 and 2020 (n=82,834-94,714). Multiple ordinal logistic regression models were fitted using the generalised estimation equation method to assess the strength of relationship between the dependent (sense of security) and independent (demographics, health and care-related factors) variables.RESULTS: The sense of security tended to increase between 2016 and 2020, and was significantly associated with being a woman, living outside big cities, being granted more home care services hours or being diagnosed/treated for depression (cumulative odds ratio 2-9% higher). Anxiety, poor health and living alone were most strongly associated with insecurity (cumulative odds ratio 17-64% lower). Aside from overall satisfaction with home care services, accessibility and confidence in staff influenced the sense of security most.CONCLUSIONS: We stress the need to promote older adults' sense of security for safe ageing in place, as mandated by Swedish law. Home care services profoundly influence older adults' sense of security. Therefore, it is vital to prioritise continuity in care, establish trust and build relationships with older adults. Given the increasing shortage of staff, integrating complementary measures, such as welfare technologies, is crucial to promoting this sense of security.
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| 7. |
- Kroese, Adrien, et al.
(author)
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3D pose estimation to detect posture transition in free-stall housed dairy cows
- 2024
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In: Journal of Dairy Science. - 0022-0302 .- 1525-3198.
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Journal article (peer-reviewed)abstract
- Free stall comfort is reflected in various indicators, including the ability for dairy cattle to display unhindered posture transition movements in the cubicles. To ensure farm animal welfare, it is instrumental for the farm management to be able to continuously monitor occurrences of abnormal motions. Advances in computer vision have enabled accurate kinematic measurements in several fields such as human, equine and bovine biomechanics. An important step upstream to measuring displacement during posture transitions is to determine that the behavior is accurately detected. In this study, we propose a framework for detecting lying to standing posture transitions from 3D pose estimation data. A multi-view computer vision system recorded posture transitions between Dec. 2021 and Apr. 2022 in a Swedish stall housing 183 individual cows. The output data consisted of the 3D coordinates of specific anatomical landmarks. Sensitivity of posture transition detection was 88.2% while precision reached 99.5%. Analyzing those transition movements, breakpoints detected the timestamp of onset of the rising motion, which was compared with that annotated by observers. Agreement between observers, measured by intra-class correlation, was 0.85 between 3 human observers and 0.81 when adding the automated detection. The intra-observer mean absolute difference in annotated timestamps ranged from 0.4s to 0.7s. The mean absolute difference between each observer and the automated detection ranged from 1.0s to 1.3s. There was a significant difference in annotated timestamp between all observer pairs but not between the observers and the automated detection, leading to the conclusion that the automated detection does not introduce a distinct bias. We conclude that the model is able to accurately detect the phenomenon of interest and that it is equatable to an observer.
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| 8. |
- Lee, Youngjo, et al.
(author)
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Estimating zones of influence using threshold regression
- 2020
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Reports (other academic/artistic)abstract
- In environmental impact assessments, it is important to be able to estimate influence of anthropogenic activities on animal populations. To quantify the influence, it is common to estimate how far, in distance, from a given disturbance source there is an influence on the animals’ habitat selection through estimating a zone of influence (ZOI). Usually, ZOI is estimated for one disturbance source at a time. In this work, we demonstrate how threshold regression modelling can be used for estimating ZOI from several possible sources of disturbances, simultaneously. Based on the theoretical properties of different estimation methods for the estimation of threshold regression we select a set of estimation methods and compare their merits through a simulation study and a real data example. The simulation results revealed that Adaptive Lasso, and Hierarchical likelihood (HL) methods, are two reasonable methods for dealing with the problem. HL performed better than Adaptive Lasso in that it had much higher success rate in identifying correct threshold with small sample size whereas Adaptive Lasso requires large sample to assure good performance. While Adaptive lasso needed to be aided with suitable weights, which are not easy to find, HL method did not require any prior weights. These two methods were applied to estimate the ZOI around 40 wind turbines and surrounding public roads on reindeer habitat selection in winter, by using GPS positioning data from 42 reindeer in north of Sweden in December to March (2012-2015). The results showed that both the disturbance sources have a negative effect on reindeer habitat selection in winter. The HL approach showed that the negative ZOI from the nearest wind turbine was 1.8 km (approx.), however the trend of higher selection of areas further away from the wind turbines was evident up to 4 km (approx.) from the active wind turbines.
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| 9. |
- Li, Yujiao
(author)
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Who benefits when IKEA enters local markets in Sweden? : An empirical assessment using difference-in-difference analysis, synthetic control methods, and Twitter sentiment analysis
- 2018
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Doctoral thesis (other academic/artistic)abstract
- Policy makers often spend considerable amounts of money to attract IKEA to their region despite not having any empirical measurements on its expected contribution to the local economy. As such, an empirical study of the economic and social impact of new IKEA stores can aid political decision making, and contribute to the literature regarding how big-box retail entry affects the regions where they enter.This dissertation aims to estimate: the impact of IKEA entry on incumbent retailers productivity, and investigate if the impact is heterogenus depending on local maket size, type of retail industry, distance to surrounding retailers, and firm size; IKEA entry effects on the average labor productivity in durable goods retailing in the entry regions; and, finally, public opinions regarding IKEA entry.For IKEA entry effects on incumbent retailers, Paper I~III separately examine four factors of potential heterogeneity. Paper I finds that market size matters: smaller rural regions have bigger IKEA effects. Paper II considers two factors: firm industry and distance, and confirms that IKEA entry effects dissipate over distance. The positive impact of IKEA entry on incumbent retailers is limited to those selling complementary goods to IKEA. No positive effects were found for the urban entry in Gothenburg in the two first papers, which is somewhat surprising. Paper III found that a positive effect exist also in Gothenburg, but it is limited to relatively small incumbent retailers with a capital stock below 1 500 000 SEK. Policy making tends to consider IKEA overall effects on entry municipalities besides IKEA spillover effects on firms. Paper V shows that rural regions are affected by IKEA entry, while larger urban markets are not.For the social effects of IKEA, Paper VI uses Twitter text mining to study public opinions regarding IKEA entry into local markets. The new IKEA stores under study caught significant public attention at the time of entry, with mostly positive attitudes toward the new stores. The favorite topics for discussion at the time of the different IKEA entries were heterogeneous depending on location.Methodologically, Paper I uses traditional Difference-in-Difference (DID) to have an initial understanding of IKEA entry spillover effects in four regions; Paper II extends to Spatial DID to catch the spatial interaction between firms; Paper III uses Panel Smooth Transition Regression to identify heterogenous effects due to firms size. Paper IV investigates a new treatment effects estimation aproach, Synthetic Control Method (SCM), to explore when the SCM is powerful, and how to improve its performance; Paper V then uses SCM to estimate IKEA effects at municipality level. In addition, to make SCM developed readily available for other researchers, the author of this thesis also published one web-application to implement a synthetic control method power test, and another to implement parametric & non-parametric estimation and inference. These findings confirm that IKEA has a positive effect on the regions where they enter. Nevertheless, governments that are to decide if to allow a big-box retail entry into their local community should be aware that the impact of such entry will depend on the size of the existing retail market, the type of existing retail industry, and the size of existing retailers in the entry region.
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| 10. |
- Marmstål Hammar, Lena, 1979-, et al.
(author)
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Being Treated With Respect and Dignity? : Perceptions of Home Care Service Among Persons With Dementia
- 2021
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In: Journal of the American Medical Directors Association. - New York : Elsevier. - 1525-8610 .- 1538-9375. ; 22:3, s. 656-662
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Journal article (peer-reviewed)abstract
- Objective: Studies on the quality of home care services (HCS) offered to persons with dementia (PwDs) reveal the prevalence of unmet needs and dissatisfaction related to encounters and a lack of relationships with staff. The objective of this study was to enhance knowledge of the perceptions of PwDs regarding their treatment with dignity and respect in HCS over time.Design: A mixed longitudinal cohort study was designed to study trends in the period between 2016 and 2018 and compare the results between PwDs (cases) and persons without dementia (controls) living at home with HCS.Setting and Participants: Persons aged 65 years and older with HCS in Sweden.Methods: Data from an existing yearly HCS survey by the Swedish National Board of Health and Welfare (NBHW) was used. The focus was on questions concerning dignity and respect. NBHW data sets on diagnoses, medications, HCS hours, and demographic information were also used. We applied GEE logistic and cumulative logit regression models to estimate effects and trends of interest after controlling for the effects of age, gender, self-rated health, and number of HCS hours.Results: Over the study period, 271,915 (PwDs¼8.1%) respondents completed the survey. The results showed that PwDs were significantly less likely (3%-10% lower odds and cumulative odds) than controls to indicate that they were satisfied in response to questions related to dignity and respect. Both groups experienced a decrease in satisfaction from 2016 to 2018. Females, individuals with poor self-rated health, and individuals granted more HCS hours were found to be more dissatisfied.Conclusions and Implications: The HCS organization needs to shift from a task-oriented system to a person-centered approach, where dignity and respect are of the utmost importance. The HCS organizations need to be developed to focus on competence in person-centered care, and leadership to support staff.
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