| 1. |
- Olande, Oduor
(author)
-
Students' narratives from graphical artefacts : Exploring the use of mathematics tools and forms of expression in students' graphicacy
- 2013
-
Doctoral thesis (other academic/artistic)abstract
- The research concerns presented in this dissertation addresses aspects of students’ interaction with commonly occurring graphical artefacts in teaching and learning environments. In particular, focus is on how the students make sense of these artefacts in relation to subject specific tools and forms of expression.The dissertation comprises of four studies guided by a semiotics cultural- historical perspective to cognition. The first study which is largely quantitative, analyses the percentage scores from students’ responses to selected items from OECD PISA surveys for items containing graphical elements. The second and the third studies in keeping with a more sociocultural perspective to learning as point of departure, examine the students’ collaborative interaction around tasks containing graphical elements. The fourth study explores the nature of students’ solutions from the Swedish national test in mathematics based on a tools and forms of expression sensitive empirically derived construct of Identification contra Critical-analytical approach to graphicacy.The main outcomes of these studies can be summarised as follows: first there is justification for re-examining the predominant characterisation of students’ interaction with graphical artefacts. Secondly, while it is not uncommon for students to take a more visual-perceptive and intuitive approach to graphicacy, results from task items interactions indicate that a Critical-analytical approach seems to be more reliable and capable of yielding desirable outcomes. The outcomes of these studies call for vigilance on the type of tasks used in relation to graphicacy and how these can be used to foster students’ Critical-analytical disposition.
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| 2. |
- Olsson, Helén, 1961-
(author)
-
Att minska risken för våld och att främja återhämtning i den rättspsykiatriska vården : Patienters och personalens erfarenheter av vägen mot återhämtning
- 2013
-
Doctoral thesis (other academic/artistic)abstract
- Detta avhandlingsarbete är utfört inom en rättspsykiatrisk vårdkontext och återspeglar patienters[1] och personals[2] erfarenheter och upplevelser av vändpunkter i samband med minskad risk för våld och återhämtning. Med utgångspunkt från ett holistiskt och salutogent hälsovetenskapligt perspektiv har avhandlingen ett tvärvetenskapligt förhållningssätt. Teoretiska ämnesdiscipliner såsom psykiatrisk omvårdnad, kriminologi och sociologi har influerat arbetet.Avhandlingens övergripande syfte var att utifrån de salutogena aspekterna i det rättspsykiatriska omvårdnadsarbetet undersöka vad som är relaterat till vändpunkter i samband med minskad risk för våld och vad som bidrar till återhämtning. Avhandlingen baseras på fyra olika studier. Syftet med den inledande kvantitativa delstudien (I) var att identifiera och jämföra rättspsykiatriska patienter som sänkt sin bedömda risk för våld med 30 % eller mer enligt riskbedömningsinstrument HCR-20. Resultatet visade att den bedömda risken för våld minskade över tid. En demografisk analys genomfördes för att studera skillnader mellan de patienter som sänkt sin bedömda risk för våld och de som inte sänkt sin risk. Det framgick att rättspsykiatriska patienter som bedömts med hjälp av riskbedömningsinstrumentet HCR-20, minskade den bedömda risken för våld, både på kort och på lång sikt. Den rättspsykiatriska vården fungerade bäst när det gällde att förbättra de kliniska riskfaktorerna (C-skalan).Riskhanteringen (R-skalan) gällande eventuell utskrivning och framtida friförmåner visade inte samma goda progress. Demografiska karaktäristika såsom ålder, alkohol och drogmissbruk och psykiatriska diagnoser var inte relaterade till minskad risk för våld, dock var kvinnliga patienter och patienter utan psykopatidiagnos mer benägna att sänka sin risk för våld. Ett urval av de patienter som minskade sin risk för våld med 30 % eller mer utgjorde basen för delstudie II och III.I delstudie II intervjuades tretton rättspsykiatriska patienter om upplevelser och erfarenheter kring vad som bidrar till minskad respektive ökad risk för våld inne på en rättspsykiatrisk avdelning. Data analyserades med hjälp av en tolkande beskrivning (Interpretive Description). Studien visade att orsakerna till ökad respektive minskad risk för våld var processrelaterad, där interaktioner mellan personal och patienter bidrog till en utveckling som antingen präglades av välbefinnande eller disharmoni. Delstudie II utgjorde en viktig kunskapskälla som präglade ansatsen i delstudie III och IV. Detta med hänvisning till att flertalet patienter i delstudie II lämnade intressanta beskrivningar av vändpunkter i samband med minskad risk för våld och återhämtning.Sålunda intervjuades i delstudie III, tio rättspsykiatriska patienter om deras upplevelser av förändringsprocesser i samband med vändpunkter och återhämtning. Dataanalysen skedde med hjälp av en kvalitativ innehållsanalys. Processen beskrevs utifrån tre faser där man i högriskfasen upplevde kaotiska och överväldigande känslor. Vändpunkten upplevdes som ett känsligt skede som präglades av att tvingas hitta en ny, konstruktiv väg i livet. Återhämtningsfasen präglades av ett accepterande och en mognad. Stöd och erkännande från omgivningen ansåg främja dessa processer.Delstudie IV bestod av intervjuer med tretton personal. Syftet var att belysa upplevelser och erfarenheter kring rättspsykiatriska patienters vändpunkter och återhämtning. Kvalitativ innehållsanalys användes för att analysera data. Beskrivningar kring hur en vändpunkt kunde bevaras och främjas baserades på vikten av att vara uppmärksam, lyhörd och att inte skynda på processen. En vändpunkt upplevdes genom att patienten uppvisade synbara positiva förändringar. Sammansättningen på personalen och patienterna ansågs påverka atmosfären på avdelningen, och bidrog till huruvida processen mot vändpunkter och återhämtning underlättades eller försvårades.Avhandlingen visar hur ett ständigt växelspel mellan patienter och mellan personal bidrog till huruvida vårdatmosfären upplevdes såsom hälsofrämjande eller ej. Vidare framgår att processer kring vändpunkter i samband med minskad risk för våld och återhämtning präglades av känslor av sårbarhet och utsatthet. Processen beskrevs som ett känsligt förlopp som behövde understödjas av förtroendefulla relationer med andra, samt möjligheter att få vistas i en trygg miljö.[1] Den vetenskapliga litteraturen använder sig av begrepp såsom client, consumer, service user eller forensic patient för att beteckna människor som är inskrivna inom den rättspsykiatriska vården. Inom det psykiatriska svenska fältet kan begreppen brukare, vårdtagare eller patient förekomma. I denna avhandling kommer begreppet patient och vårdtagare omväxlande att användas för att beteckna de människor som är föremål för den rättspsykiatriska vården. De patienter som deltagit i avhandlingens två delstudier kommer omväxlande att benämnas såsom deltagare eller patienter, för att åstadkomma en varierande och läsvänlig text.[2] I denna avhandling anser begreppet personal den personalkategori som arbetar med omvårdnad inom en rättspsykiatrisk kontext. Det är främst sjuksköterskor och skötare som inkluderas i begreppet omvårdnadspersonal inom den vetenskapliga litteraturen. Sjuksköterskor benämns såsom registered mental health nurses eller registered nurses. Övrig omvårdnadspersonal tituleras till exempel som nurse manager eller assistant nurses. När begreppen personal, vårdare eller omvårdnadspersonal används i denna avhandling avses då den personalkategori som arbetar närmast patienten med omvårdnad och ingen åtskillnad kommer att göras mellan de båda yrkesgrupperna. Personalen som deltar i delstudie IV har omväxlande kallats för personal eller vårdare.
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| 3. |
- Nydahl, Erik, 1983-
(author)
-
I fyrkens tid : Politisk kultur i två ångermanländska landskommuner
- 2010
-
Doctoral thesis (other academic/artistic)abstract
- Abstract Nydahl, Erik; I fyrkens tid. Politisk kultur i två ångermanländska landskommuner 1860-1930 [Voting by income: The political culture of two Swedish municipalities, 1860–1930] Department of Humanities, Mid Sweden University, SE-871 88 Härnösand, Sweden ISBN: 978-91-86694-05-0, ISSN 1652-893X, Doctoral thesis nr: 100 (2010). Swedish text with a summary in English This dissertation analyses the development of political culture in two Swedish municipalities between the 1860s and the 1930s – a period during which Swedish society underwent major changes. The purpose is to examine the direct and indirect consequences of an evolving industrial society's economic, social and political structures on political culture at local levels. The following factors are the base of the study. At the start of the 1860s, a long-standing Swedish tradition of local self-government was reinforced through a major reform, the Local Government Ordinance of 1862 (1862 års kommunalförfattningar). From this point, each parish formed its own municipality. The new municipalities were given the right to levy taxes and made responsible for welfare and schools, thereby becoming a prominent arena for the exercise of power at local levels. The municipal reform of 1862 was carried out at a time when Swedish society was transitioning as the industrialisation process accelerated during the latter part of the 1800s. Gradually, the old structure of an agricultural society was cast aside in favour of a new, modern industrial society. Naturally, also the municipalities changed – directly and indirectly. For some municipalities, adjustments were significant; for others, less so. Part of this process was the reformation of voting rights from plutocratic to public and equal. Another part was the reorganisation of municipal government from direct government via municipal meetings to representative government via municipal councils. Two main issues are formulated and answered in the dissertation. The one addresses who or which had the power over local politics and how the situation changed over time. The second addresses in what way municipal representation changed form with the modernisation of the municipalities. The empirical survey comprises a comparative case study between two municipalities in the northern part of Sweden. The one municipality, Ytterlännäs, was early the site for large-scale sawmill industry. The second municipality, Stigsjö, retained its agricultural structure throughout the entire period in question. The comparison makes it possible to analyse the impending industrial society from two different poles. In the 1800s, local politics was considered to be a completely different sort than politics at a national level. The difference was that local politics, referred to as “the municipal”, was seen as non-political and unaffiliated with those conflicts addressed at national levels, referred to as “the political”. The dissertation demonstrates two different models of how modern municipal politics evolved from the municipal meetings of the 1800s. While the starting point was the same in both municipalities, the paths diverged in the early 1870s. In the agricultural municipality of Stigsjö, it was “business as usual”. In the industrial municipality of Ytterlännäs, however, confrontation arose between enterprises and farmers and eventually, a labour movement emerged demanding the right of participation. The dissertation shows that the distinction between “municipal” and “political” was obliterated in the beginning of the 1900s, paving the way for a new concept – municipal politics. This process occurred in a very palpable way in Ytterlännäs but eventually, Stigsjö was forced to conform. The new municipal politics was, so to speak, the final station in both municipalities. In conjunction with party politicisation of local politics, the criteria and seats for the municipal representatives changed. When party affiliation became an important criterion, professional affiliation became less relevant. Party bloc seats replaced the independent seats, and representatives were eventually paid remuneration. Keywords: Political culture, politics, voting right, municipal politics, industrial society, industrialisation, elected representatives, representation, temperance movement, labour movement, popular movements, political parties, modernisation
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| 4. |
- Abbasi, Seyed
(author)
-
Determinants of social inequalities in cardiovascular disease among Iranian patients
- 2018
-
Doctoral thesis (other academic/artistic)abstract
- Background and objectives: Cardiovascular disease (CVD) is the single largest cause of mortality in the world. Similar to other health issues, CVD is generally affected either by individual risk factors, which may influence the risk for developing an illness or its complications, or by social indicators (social determinants of health). There is evidence from developed countries which shows that the so-called "upstream factors"—including social determinants such as political, social, spiritual, cultural, and economic factors—may affect the prevalence and incidence of CVD. Scarce evidence from studies in low- and middle-income countries also suggests that social factors may affect the distribution of CVD across population groups. However, there is a dearth of such data in Iran, where only a few small-sizedstudies have focused on the social determinants of health. Therefore, the present thesis sought to fill this gap by assessing the effects of socioeconomic status (SES) on the distribution of CVD and the relevant inequalities within the Iranian context.Methods: This thesis is based on four studies, which used data from the Tehran Heart Center’s Databases. In Study I, a total of 44,820 patients who underwent coronary angiography at Tehran Heart Center between 2005 and 2010 were recruited. Then, their pre- and post-procedural data—including demographics, CVD risk factors, symptoms, and laboratory tests—were compared between men and women. In Study II, 6,246 patients with acutecoronary syndrome who were hospitalized between March 2004 and August 2011 were included and, based on their education and their employment status, were divided into high- and low-SES groups. Thereafter, the effect of SES on the in-hospital death of the patients was evaluated. In Study III, 20,165 patients with documented coronary artery disease who underwent coronary angiography at Tehran Heart Center were enrolled and CVD risk factors and severity (measured by the Gensini score) were assessed among the six major Iranian ethnic groups. In Study IV, 9,088 patients with acute coronary syndrome who were hospitalized at Tehran Heart Center between May 2007and June 2014 were recruited and the association between in-hospital death due to acute coronary syndrome and place of residence (rural/urban) was assessed using logistic regression adjusted for potential confounders.Results: In this thesis, the data analyses were based on the hypothesis that there is a potential association between the different socioeconomic indicators and the selected cardiovascular outcomes. In Study I, among the recruited participant, 25,363 men and 11,995 women had coronary artery disease and the women not only were significantly older, less educated, and more overweight but also had higher blood levels of triglyceride, cholesterol, low-density lipoprotein, high-density lipoprotein, and fasting blood sugar than the men. Moreover, hypertension and diabetes mellitus showed the strongest association in the women with coronary artery disease (OR=3.45, 95% CI: 3.28to 3.61 and OR=2.37, 95% CI: 2.26 to 2.48, respectively). In addition, the frequency of post-procedural recommendations for non-invasive procedures was higher in the women than in the men (20.1% vs 18.6%; P<0.001). In StudyII, of the 6,246 recruited patients with acute coronary syndrome, 3,290individuals were considered low-SES and 2,956 high-SES individuals. In-hospital death occurred in 79 (1.26%) patients: 1.9% in the low-SES and 0.6% in the high-SES groups. After adjustment for the possible cofounders, our multivariate analysis demonstrated a significant effect of the patients’ SES on their in-hospital death and a lower in-hospital mortality rate was shown in the high-SES patients (OR=0.30, 95% CI: 0.09 to 0.98; P=0.046). In Study III, the Fars (8.7%) and Gilak (8.6%) ethnic groups had the highest frequency of having at least four simultaneous risk factors. Additionally, the mean Gensini score was lowest in the Lurs (67.5±52.8) and highest among the Gilaks (77.1±55.9). The multivariable regression analysis indicated that the Gilaks showed the worst CVD severity (β: 0.056, 95% CI: 0.009 to 0.102; P=0.018), followed by the Turks (β: 0.032, 95% CI: 0.005 to 0.059; P=0.020), and the lowest CVD severity, was detected in the Lurs (β: -0.087, 95% CI: -0.146 to -0.027;P=0.004). Study IV showed that while smoking (P=0.002), positive family history of coronary artery disease (P=0.003), higher body mass index (P=0.013),and hyperlipidemia (P=0.026) were more prevalent in the urban patients, the rural patients showed lower educational levels (P<0.001) and higher frequency of unemployment (P=0.009). Meanwhile, in-hospital death occurred in 135 (1.5%) patients: 125 (1.5%) urban and 10 (1.2%) rural. To adjust the effects of the possible confounders, we utilized the Firth regression model, which showed no significant difference regarding in-hospital death betweenthe rural and urban patients (OR=1.57, 95% CI: 0.376 to 7.450; P=0.585).Conclusions: The aim of this thesis was to investigate the effects of social determinants (particularly SES) on CVD and its modifiable risk factors among Iranian patients. Results showed that medical treatment for CVD was more recommended (by treating physicians) to the women than the men, and the low-SES patients with acute coronary syndrome were more likely to die in the hospital than their high-SES counterparts. In addition, the thesis found heterogeneity in the distribution of the traditional risk factors for CVD as well as CVD severity in the major Iranian ethnic groups. Further, there were no differences concerning the in-hospital death rates due to acute coronary syndrome between the urban and rural patients after adjustment for the potential confounders.
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| 5. |
- Afewerki, Samson, 1985-
(author)
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Development of catalytic enantioselective C-C bond-forming and cascade transformations by merging homogeneous or heterogeneous transition metal catalysis with asymmetric aminocatalysis
- 2014
-
Doctoral thesis (other academic/artistic)abstract
- Chiral molecules play a central role in our daily life and in nature, for instance the different enantiomers or diastereomers of a chiral molecule may show completely different biological activity. For this reason, it is a vital goal for synthetic chemists to design selective and efficient methodologies that allow the synthesis of the desired enantiomer. In this context, it is highly important that the concept of green chemistry is considered while designing new approaches that eventually will provide more environmental and sustainable chemical synthesis.The aim of this thesis is to develop the concept of combining transition metal catalysis and aminocatalysis in one process (dual catalysis). This strategy would give access to powerful tools to promote reactions that were not successful with either transition metal catalyst or the organocatalyst alone. The protocols presented in this thesis based on organocatalytic transformations via enamine or iminium intermediates or both, in combination with transition metal catalysis, describes new enantioselective organocatalytic procedures that afford valuable compounds with high chemo- and enantioselectivity from inexpensive commercial available starting materials. In paper I, we present a successful example of dual catalysis: the combination of transition metal activation of an electrophile and aminocatalyst activation of a nucleophile via enamine intermediate. In paper II, the opposite scenario is presented, here the transition metal activates the nucleophile and the aminocatalyst activates the electrophile via an iminium intermediate. In paper III,we present a domino Michael/carbocyclisation reaction that is catalysed by a chiral amine (via iminium/enamine activation) in combination with a transition metal catalysts activation of an electrophile. In paper IV, the concept of dual catalysis was further extended and applied for the highly enantioselective synthesis of valuable structural scaffolds, namely poly-substituted spirocyclic oxindoles. Finally, in paper V the concept of dual catalysis was expanded, by investigating more challenging and environmentally benign processes, such as the successful combination of a heterogeneous palladium and amine catalysts for the highly enantioselective synthesis of functionalised cyclopentenes, containing an all carbonquaternary stereocenter, dihydrofurans and dihydropyrrolidines.
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| 6. |
- Ahlin, Karin, 1963-
(author)
-
Benefits of Digital Technical Information
- 2020
-
Doctoral thesis (other academic/artistic)abstract
- In our daily work life, we use a wealth of information, including a category of information produced as a part of products and their life-cycle phases, named digital technical information (DTI). Manufacturing organizations focus more often on the product than on DTI, because DTI’s impact seems almost invisible, despite its crucial role to the product and its life-cycle phases, development, production, maintenance, and destruction. Hence, the aim of this thesis is to describe DTI’s benefits and the research questions: “What are the benefits of the DTI?” and “What are the perceptions of how to measure benefits of DTI?” The thesis contains five studies related to identifying and measuring DTI’s benefits. The empirical material is based on semi-structured interviews and group interviews within five organizations and a survey among manufacturing organizations in Sweden.I used three characteristics of the DTI and two pairs of previously known benefit categories to analyse the benefits. The analysis shows that the benefits are recognized in the particular product’s life cycle phase where the DTI is published. However, the DTI continues to offer benefits in the product’s other life cycle phases. In relationship to the product, the benefits evolve from supporting an individual product to supporting more general product lines or all products and a more complex product is said to increase DTI’s benefits. DTI’s structure adds benefits as synthesized or aggregated DTI, where the DTI is synthesized or aggregated automatically or manually. The categorization predetermined benefits related to the change are less numerous than the emerging benefits. The predetermined benefits are strategic by nature, and the emerging ones are mainly used to achieve operational goals. Measuring DTI’s benefits is of importance for a formal comparison of its development and is of special interest for managers. Perceptions from the initial stages on how to measure show that to establish common interpretations among the stakeholders of the measurement process is of importance, especially when it comes to what is viewed as a benefit. The benefits are viewed as intangible by the respondents, which creates difficulties when one is evaluating, using conventional measurement methods. The only perceived way to measure is when DTI reduces co-worker’s workload and efficiency is achieved. The thesis’s contribution to academia consists of the analysis of DTI’s benefits, showing details of the relationships between the DTI and its benefits. For practice, the contributions focus on the systematic evaluation process, which can be used for further development of the DTI and comparison of the evolvement of the DTI itself and relating to other resources. One proposal for future research is to use the analysed benefits and compare various approaches to digitizing DTI, e.g. Industry 4.0. Another proposal is to list, in detail, various ways on how to measure DTI’s benefits and their usefulness. The latter can positively impact on any intangible benefits due to the general approach we have established of how to measure those benefits.
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| 7. |
- Ahmad, Jawad, 1985-
(author)
-
Development and Characterization of Large Area Pressure Sensors and Sitting Posture Monitoring Systems
- 2021
-
Doctoral thesis (other academic/artistic)abstract
- With the emergence of the Internet and rapid development of science and technology over the past few decades, many individuals worldwide now rely on the Internet to conduct daily activities ranging from education, business and creativity to communication and shopping. As we tend to spend more and more time on the Internet and engage less in physical activities, this persistent behaviour could result in some health-related issues within a relatively short period of time. This behaviour, known as sedentary lifestyle, may be related to a higher risk of cardiovascular disease, osteoporosis, obesity, anxiety, pressure ulcers and many other illnesses. As a consequence, there has been great interest in developing non-invasive and unobtrusive measurement techniques for a variety of health care-monitoring applications, such as for blood oxygen saturation, stress levels, electrocardiograms and glucose monitoring. In such systems, wearable and flexible electronics technologies may enable monitoring of vital signs, offering significant potential for early screening as well as long-term behaviour modelling.In this thesis, large area pressure sensors based on non-conventional materials are proposed and realised by screen printing technique for monitoring sitting postures. The developed pressure sensing system measures distributed pressure when an individual sits on a chair equipped with a pressure sensor array. This technology could provide grounding for the advancement of health-related monitoring systems for both able-bodied and disabled individuals and inform them of their sitting time and sitting posture, and this could be used to establish a sitting pattern. To accomplish this, pressure sensors have been designed using non-conventional flexible electronics. A blend of non-conductive and low-resistance ink is used as pressure-sensitive material to enable the realization of screen-printed sensors. To characterise the performance of the suggested pressure sensor, several tests, such as repeatability, drift and flexibility, are conducted. The sensor has also been exposed to different humidity and temperature conditions in a climate chamber to examine its functionalities.A graphical user interface was developed for real-time demonstration of data from distributed pressure points in the form of a pressure map to display the pressure values. Four sitting postures are identified: forward, backward, left, and right leaning. Furthermore, a stretchable pressure sensor is proposed that could follow slight stretching with regard to changes in the shape of the human skin. Machine learning algorithms have been employed to further enhance the sitting posture identification, and accuracy of 99.03% is attained. A standalone embedded system capable of illustrating real-time pressure data has been developed with the potential to be used in portable health monitoring systems. In summary, this work provides a promising framework for measuring pressure distribution and identifying irregular sitting postures that may help to reduce the potential risks of developing health-related issues associated with prolonged sitting time.
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| 8. |
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| 9. |
- Ahmad, Waqas
(author)
-
High Efficiency Light Field Image Compression : Hierarchical Bit Allocation and Shearlet-based View Interpolation
- 2021
-
Doctoral thesis (other academic/artistic)abstract
- Over the years, the pursuit of capturing the precise visual information of a scenehas resulted in various enhancements in digital camera technology, such as highdynamic range, extended depth of field, and high resolution. However, traditionaldigital cameras only capture the spatial information of the scene and cannot pro-vide an immersive presentation of it. Light field (LF) capturing is a new-generationimaging technology that records the spatial and angular information of the scene. Inrecent years, LF imaging has become increasingly popular among the industry andresearch community mainly for two reasons: (1) the advancements made in optical and computational technology have facilitated the process of capturing and processing LF information and (2) LF data have the potential to offer various post-processing applications, such as refocusing at different depth planes, synthetic aperture, 3Dscene reconstruction, and novel view generation. Generally, LF-capturing devicesacquire large amounts of data, which poses a challenge for storage and transmissionresources. Off-the-shelf image and video compression schemes, built on assump-tions drawn from natural images and video, tend to exploit spatial and temporalcorrelations. However, 4D LF data inherit different properties, and hence there is aneed to advance the current compression methods to efficiently address the correla-tion present in LF data.In this thesis, compression of LF data captured using a plenoptic camera andmulti-camera system (MCS) is considered. Perspective views of a scene capturedfrom different positions are interpreted as a frame of multiple pseudo-video se-quences and given as an input to a multi-view extension of high-efficiency videocoding (MV-HEVC). A 2D prediction and hierarchical coding scheme is proposedin MV-HEVC to improve the compression efficiency of LF data. To further increasethe compression efficiency of views captured using an MCS, an LF reconstructionscheme based on shearlet transform is introduced in LF compression. A sparse set of views is coded using MV-HEVC and later used to predict the remaining views by applying shearlet transform. The prediction error is also coded to further increase the compression efficiency. Publicly available LF datasets are used to benchmark the proposed compression schemes. The anchor scheme specified in the JPEG Plenocommon test conditions is used to evaluate the performance of the proposed scheme. Objective evaluations show that the proposed scheme outperforms state-of-the-art schemes in the compression of LF data captured using a plenoptic camera and an MCS. Moreover, the introduction of shearlet transform in LF compression further improves the compression efficiency at low bitrates, at which the human vision sys-tem is sensitive to the perceived quality.The work presented in this thesis has been published in four peer-reviewed con-ference proceedings and two scientific journals. The proposed compression solu-tions outlined in this thesis significantly improve the rate-distortion efficiency forLF content, which reduces the transmission and storage resources. The MV-HEVC-based LF coding scheme is made publicly available, which can help researchers totest novel compression tools and it can serve as an anchor scheme for future researchstudies. The shearlet-transform-based LF compression scheme presents a compre-hensive framework for testing LF reconstruction methods in the context of LF com-pression.
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| 10. |
- Ainegren, Mats
(author)
-
Roller skis' rolling resistance and grip characteristics : influences on physiological and performance measures in cross-country skiers
- 2012
-
Doctoral thesis (other academic/artistic)abstract
- The aim of this thesis was to investigate roller ski characteristics; classical and freestyle roller skis’ rolling resistance coefficients (μR) and classical style roller skis’ static friction coefficients (μS), and to study the influence of different μR and μS on cross-country skiers’ performance and both physiological and biomechanical indices. The aim was also to study differences in skiing economy and efficiency between recreational skiers, female and male junior and senior elite cross-country skiers.The experiments showed that during a time period of 30 minutes of rolling on a treadmill (warm-up), μR decreased significantly (p<0.05) to about 60-65 % and 70-75 % of its initial value for freestyle and classical roller skis respectively. Also, there was a significant influence of normal force on μR, while different velocities and inclinations of the treadmill only resulted in small changes in μR.The study of the influence on physiological variables of a ~50 % change in μR showed that during submaximal steady rate exercise, external power, oxygen uptake, heart rate and blood lactate were significantly changed, while there were non-significant or only small changes to cycle rate, cycle length and ratings of perceived exertion. Incremental maximal tests showed that time to exhaustion was significantly changed and this occurred without a change in maximal power, maximal oxygen uptake, maximal heart rate and blood lactate, and that the influence on ratings of perceived exertion was non-significant or small.The study of classical style roller skis μS showed values that were five to eight times more than the values of μS reported from on-snow skiing with grip-waxed cross-country skis.The subsequent physiological and biomechanical experiments with different μS showed a significantly lower skiing economy (~14 % higher v̇O2), higher heart rate, lower propulsive forces coming from the legs and shorter time to exhaustion (~30 %) when using a different type of roller ski with a μS similar to on-snow skiing, while there was no difference between tests when using different pairs of roller skis with a (similar) higher μS.The part of the thesis which focused on skiing economy and efficiency as a function of skill, age and gender, showed that the elite cross-country skiers had better skiing economy and higher gross efficiency (5-18 %) compared with the recreational skiers, and the senior elite had better economy and higher efficiency (4-5 %) than their junior counterparts, while no differences could be found between the genders.
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| 11. |
- Alam, Mohammad Anzar
(author)
-
Online optical method for real-time surface measurement using line-of-light triangulation
- 2013
-
Doctoral thesis (other academic/artistic)abstract
- Real time paper surface-web measurement is one of the challenging research fields. The traditional laboratory method has many limitations and is unable to measure the entire tambour during the manufacturing process. It has been necessary to develop an online technique that could measure the surface topography in real time. An optical technique was developed, based on laser triangulation, and is applied to develop a new prototype device, which characterizes high speed paper-web surfaces over a wide scale of spatial wavelengths spectrum and computes the surface roughness in real time. The used multi channel pulsed laser diode, source of illumination onto the paper-web, is of benefit due to its low coherence length and is capable to deliver a powerful burst of light beam over a 1 µs duration, which delivers energy of 100 µJ per pulse. The short exposure time avoids blurriness in the acquired images which could possible due to the high speed and vibrations on the paper-web.The laser beam is shaped into a narrow line-of-light using cylindrical lenses and is projected onto a paper-web surface, which covers a physical length of about 210 mm. The created line-of-light cross section full width at half maximum, FWHM Gaussian distribution, is 2-3 pixels on the image. The line-of-light is projected onto the paper-web perpendicular to the plane of the surface. The low angled, low specular, reduced coherence length, scattered reflected laser line is captured by the 3 CCD sensors, which are synchronized with the laser source. The low specular light ensures to avoid saturation of the imaging sensors if the surface is very smooth, and obliquely captures the z-directional fine feature of the surface.The scattered phenomenon of the reflected light is responsible for the surface irregularity measurements. The basic image processing algorithm is applied in order to remove noise and cropped the images widthwise so that only pixels above a preset threshold gray level can be processed, which enables efficient real time measurement. The image is transformed into a 1D array using the center of gravity, COG. The accuracy and precision of the COG depends on the line-of-light FWHM, which, in turn, is responsible for the accuracy, noise and the resolution of the developed technique. The image subpixel resolution achieved is 0.01 times a pixel and uuncertainty in the raw data is 0.43 µm while it is 0.05 µm in the rms roughness.The signal processing steps combining the B-Spline filter and the filter in the spatial frequency domain were employed in order to separate roughness, waviness, and form and position error in the raw profile. The prototype is designed to measure online surface roughness and to characterize surface in a spatial wavelength spectrum from 0.09 to 30 mm, which is extendable to any required spatial range in order to cover a wide scale surface feature such as micro roughness, macro roughness and waviness. It is proven that exploitation of a simple laser triangulation technique could lead to an improvement in the overall quality and efficiency in the paper and paperboard industries and it can also be of potential interest for the other surface characterization problems.
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| 12. |
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| 13. |
- Alimadadi, Majid
(author)
-
Foam-formed Fiber Networks: Manufacturing, Characterization, and Numerical Modeling : With a Note on the Orientation Behavior of Rod-like Particles in Newtonian Fluids
- 2018
-
Doctoral thesis (other academic/artistic)abstract
- Fiber networks are ubiquitous and are seen in both industrial materials (paper and nonwovens) and biological materials (plant cells and animal tissues). Nature intricately manipulates these network structures by varying their density, aggregation, and fiber orientation to create a variety of functionalities.In conventional papermaking, fibrous materials are dispersed in water to form a sheet of a highly oriented two-dimensional (2D) network. In such a structure, the in-plane mechanical and transport properties are very different from those in the out-of-plane direction. A three-dimensional (3D) network, however, may offer unique properties not seen in conventional paper products.Foam, i.e., a dispersed system of gas and liquid, is widely used as the suspending medium in different industries. Recently, foam forming was studied extensively to develop the understanding of foam-fiber interactions in order to find potential applications of this technology in papermaking.In this thesis, a method for producing low-density, 3D fiber networks by utilizing foam forming is investigated and the structures and mechanical properties of such networks are studied. Micro-computed tomography is used to capture the 3D structure of the network and subsequently to reproduce artificial networks. The finite element method is utilized to model the compression behavior of both the reproduced physical network and the artificial networks in order to understand how the geometry and constitutive elements of the foam-formed network affect its bulk mechanical properties. Additionally, a method was studied in order to quantify the orientation behavior of particles in a laminar Newtonian flow based on the key parameters of the flow which control the orientation.The resulting foam-formed structures were extremely bulky. Yet despite this high bulk, the fiber networks retained good structural integrity. The compression behavior in the thickness direction was characterized by extreme compressibility and high strain recovery after compression. The results from the modeling showed that the finite-deformation mechanical response of the fiber network in compression was satisfactorily captured by the simulation. However, the artificial network shows higher stiffness than the simulated physical network and the experiment. This discrepancy in stiffness was attributed to macroscopic structural non-uniformities in the physical network, which result in increased local compliance. It was also found that the friction between the fibers, as well as the fiber curvature, had a negligible impact on the compression response of the fiber network, while defects (in the form of kinks) had an effect on the response in the last stages of compression. The study of the orientation behavior of particles at different flow velocities, particle sizes, and channel geometries suggests that it might be possible to utilize the flow shear rate as a means to quantify the orientation behavior.
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| 14. |
- Alimohammadzadeh, Rana
(author)
-
Eco-friendly and Catalytic Surface Engineering of Cellulose and Nanocellulose
- 2021
-
Doctoral thesis (other academic/artistic)abstract
- The non-stop use of petroleum-based materials such as plastics can generate significant environmental problems, including pollution of the oceans and increased CO2 levels, and cause diseases like cancer due to the starting monomers. Consequently, increased use of sustainable and non-toxic polymers and monomers is required to address these issues. Cellulose, generously supplied by Mother Nature, is the most abundant biopolymer on Earth. Nanocellulose is a sustainable polymer extracted from the cellulose inwood or produced by bacteria and algae. This biodegradable nanomaterialhas recently been receiving intense research attention, since it has great potential for use in a broad range of industrial and biomedical applications. However, it has limitations such as moisture sensitivity and incompatibility with hydrophobic materials due to its hydrophilic nature. Chemical modification is necessary for it to fulfill the requirements for applications that require high moisture resistance and water repellency. Unfortunately, several of the existing methods involve harsh and toxic conditions or reagents. In this thesis, together with my co-workers, I have employed the toolbox of organocatalysis for accomplishing eco-friendly and innovative surface modification of cellulose and nanocellulose. The organocatalysts we usedmost in our research are the naturally abundant and industrially relevantorganic acids tartaric acid and citric acid.Direct catalytic esterification of cellulose nanocrystal (CNC) with thioglycolicacid was performed either in suspension or on solid surfaces such as films and foams. We found that the reaction was accelerated by tartaric acid but could also be autocatalytic with respect to the thioglycolic acid under certain conditions. The synthesized CNC-SH was further exploited as a heterogeneous reducing agent as well as a handle for further nanocellulose modifications. This was demonstrated by using CNC-SH as a heterogenous reducing agent of Cu(II) to Cu(I), which is essential for allowing the Cu to actas a catalyst for 2,3-dipolar cycloaddition reactions between azides andalkynes. We also showed that the thia-modified CNC could undergo further functionalizing via thiol-ene click chemistry reactions, for example, we attached fluorescent compounds such as TAMRA and quinidine.Herein we provide a fluorine-free method to prepare superhydrophobic CNC film with excellent water-resistance properties by combining self-assemblyand organocatalysis. Self-assembly of CNC via vacuum filtration resulted in xa film with a specific roughness at the microscale. Next, the catalytic silylation with a variety of alkoxysilanes in the presence of natural organic acids such as tartaric acid and citric acid was performed. The successful implementation of our method resulted in a super-hydrophobic CNC film (water contact angleover 150°) with excellent water-resistance. Thus, the combination of the selfassembly of a rough surface with catalytic surface modification resulted in a phenomenon like the “lotus effect” as exhibited by the leaves of the lotus flower. An investigation of the oxygen permeability of the octadecyltrimethoxysilane-modified CNC film revealed that it significantly decreased at high relative humidity compared with unmodified CNC films.In this thesis, the fabrication of hydrophobic and functionalized MTM/CNF nanocomposites using organocatalytic surface modification with a large variety of alkoxysilanes is also performed. The surface modifications are mildand the mechanical strength of the Nacre-mimetic nanocomposites is preserved. Elemental mapping analysis revealed that the silane modification occurred predominantly on the surface.A combination of organocatalyst and biopolyelectrolyte complex was appliedfor surface engineering of chemi-thermomechanical pulp (CTMP) and bleached sulfite pulp (BSP). The reaction was performed using a synergistic combination of an organocatalyst with a polyelectrolyte (PE) complex. Using this method, the strength properties of CTMP and BSP sheets were significantly increased (up to 100% in Z-strength for CTMP). Further investigations of the distribution of the PE complex were then performed using TAMRA and quinidine labeling and confocal laser scanningmicroscopy. This revealed that an even distribution of the cationic starch component of the PE complex had occurred within the CTMP-based paper sheets, which follows its lignin distribution pattern.
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| 15. |
- Alirani, Gertrud, 1976-
(author)
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Miljöintegrering i praktisk tillämpning : En policystudie av två lokala stadsutvecklingsprocesser
- 2020
-
Doctoral thesis (other academic/artistic)abstract
- Dealing with environmental problems has become one of the most challenging political issues of our time. Since the Brundtland report in 1987, environmental policy integration (EPI) that is, the mainstreaming of environmental issues in all policy sectors has emerged as a viable policy solution. This has meant that responsibility for implementing environmental policy rests to a large extent on local authorities where environmental problems with both local and global consequences are expected to be handled. However, there is still a disagreement on what EPI means in day-to-day decision making. With a theoretical framework drawing from theory on policy change, policy entrepreneurship and the neoinstitutional “logic of appropriateness” the aim of this dissertation is to analyze how the integration of environmental considerations manifests itself in local policy processes, highlighting what factors foster or hinder EPI. To reach this aim, I have followed two urban development processes in Kristianstad. This research offers insights on how EPI varies through the policy process and how focus is placed mainly on certain environmental issues and chiefly defined as of local importance. My study suggest that arenas for coordination are critical to overcoming the perceived “gap” between EPI on a strategic level and its implementation. This can help to clarify responsibility allocation among bureaucrats and their leeway for interpretation when new issues comes up continuously during the processes and affect the conditions for EPI. Furthermore, the dissertation gives insights on how acting “entrepreneurially” can enable an environmental issue to be included and given priority. This can also be a barrier if the ones acting entrepreneurially are not part of the entire process because the issue might receive less attention. In addition, if too much attention is given to one issue it might overshadow other environmental issues. Conversely, acting according to “the logic of appropriateness” can enable EPI by enhancing a more all-encompassing perspective on environmental considerations and also function as a cautious approach to radical change by preventing measures taken in absence of democratic legitimacy. By using the two theoretical perspectives, “entrepreneurial” and “appropriate” agency, this dissertation offers important insights into how different ways of acting interact and affect EPI and its outcome.
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| 16. |
- Almén, Niclas, 1971-
(author)
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Intervening Stress Recovery Behaviors in Everyday Life
- 2022
-
Doctoral thesis (other academic/artistic)abstract
- Background. High levels of perceived stress and stress-related ill health, such as burnout, are common in many countries. Several theories postulate that stress behaviors promote adaption to environmental changes and if sustained they are potentially harmful for the body. In accordance, impaired stress recovery behaviors, i.e., psychophysiological deactivation after periods of stress behaviors, have been suggested to be a critical factor in explaining stress-related ill health. Whereas research shows that interventions targeting stress reactivity can have beneficial effects on stress-related variables, studies on interventions targeting stress recovery are surprisingly few. Also, the number of validated instruments for measuring behaviors important for stress recovery are few, in particular easily used self-rating scales. Aims. The primary aim of the thesis was to evaluate stress and health-related effects of an intervention targeting stress recovery behaviors in everyday life among people perceiving high levels of stress in life. A secondary aim was to validate a self-report scale measuring behaviors important for stress recovery in everyday life. Method. Three empirical studies were conducted to evaluate effects of the behavioral stress recovery intervention “balance in everyday life”, which solely aims at strengthening stress recovery behaviors in everyday life. First, a brief version of the intervention was investigated through a small pilot study in which a single-subject experimental design was used (study 1). After that, the intervention was exploratively tested in a group format in which a quasi-experimental design was used (study 2). Due to the positive results of these two studies, a larger scale study using a randomized controlled design was conducted in order to further investigate the effects of the intervention when delivered in a group format (study 3). To fulfill the secondary aim of the thesis, the Recovery Experience Questionnaire was translated into Swedish and analyzed using exploratory factor analysis and confirmatory factor analysis (study 4). Results. In study 1, data demonstrated immediate reduction of stress symptoms as a function of the intervention. The improvements were maintained at 1-year and 5-year follow-up assessments. In study 2, in comparison with a waiting-list-control group, the intervention yielded statistically significant improvements between pre- and postintervention assessment on eleven out of twelve stress and health-related variables. Medium to large between-groups effect sizes were demonstrated for the primary outcome measures covering (potential) recovery behaviors, perceived stress and rest and experiences of being recovered. In the third study, statistically significant improvements for all outcome measures at postintervention assessment and at the 3-month follow-up were demonstrated. The between-groups effect sizes for the primary measures - perceived stress, tension, and burnout - were medium-to-high at postintervention assessment and at follow-up. In addition, in all studies the intervention was associated with beneficial changes in levels of anxiety and depression. In the last study, support was found for the proposed four-factor structure of the Swedish version of the Recovery Experience Questionnaire. Conclusions. The results clearly indicate that the intervention “balance in everyday life” improves stress and health-related factors in a relatively satisfactory way among people perceiving high levels of stress in life. The empirical support is strongest for the reduction in tension, perceived stress, burnout, anxiety and depression, and to deliver the intervention in a group format. The studies demonstrated results that warrant further investigation of the effects of “balance in everyday life”, for example in different contexts, and to study other behavioral recovery interventions. To test (potential) recovery facilitating behaviors as mediators of intervention effects, such as reduction in burnout, the Swedish version of the Recovery Experience Questionnaire could be used.
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| 17. |
- Alqaysi, Hiba
(author)
-
Cost Optimization of Volumetric Surveillance for Sky Monitoring : Towards Flying Object Detection and Positioning
- 2022
-
Doctoral thesis (other academic/artistic)abstract
- Unlike surface surveillance, volumetric monitoring deals with three-dimensional target space and moving objects within it. In sky monitoring, objects fly within outdoor and often remote volumes, such as wind farms and airport runways. Therefore, multiple cameras should be implemented to monitor these volumes and analyze flying activities.Due to that, challenges in designing and deploying volumetric surveillance systems for these applications arise. These include configuring the multi-camera node placement, coverage, cost, and the system's ability to detect and position flying objects.The research in this dissertation focuses on three aspects to optimize volumetric surveillance systems in sky monitoring applications. First, the node placement and coverage should be considered in accordance with the monitoring constraints. Also, the node architecture should be configured to minimize the design cost and maximize the coverage. Last, the system should detect small flying objects with good accuracy.Placing the multi-camera nodes in a hexagonal pattern while allowing overlap between adjacent nodes optimizes the placement. The inclusion of monitoring constraints like monitoring altitude and detection pixel resolution influences the node design. Furthermore, presented results show that modeling the multi-camera nodes as a cylinder rather than a hemisphere minimizes the cost of each node. The design exploration in this thesis provides a method to minimize the node cost based on defined design constraints. It also maximizes the coverage in terms of the number of square meters per dollar. Surveillance systems for sky monitoring should be able to detect and position flying objects. Therefore, two new annotated datasets were introduced that can be used for developing in-flight birds detection methods. The datasets were collected by Mid Sweden University at two locations in Denmark. A YOLOv4-based model for birds detection in 4k grayscale videos captured in wind farms is developed. The model overcomes the problem of detecting small objects in dynamic background, and it improves detection accuracy through tiling and temporal information incorporation, compared to the standard YOLOv4 and background subtraction.
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| 18. |
- An, Siwen
(author)
-
Spectroscopic and Microscopic X-ray Fluorescence Analysis for Environmental and Industrial Applications
- 2022
-
Doctoral thesis (other academic/artistic)abstract
- Heavy metals are well-known environmental pollutants due to its potential impact on associated ecosystems and human health. Thus, it is important to monitor the levels of heavy metals in the environment. X-ray fluorescence (XRF) analysis is a powerful and effective screening tool in measuring the concentration of multi-elements simultaneously.This thesis provides insight into development and implementation of XRF instruments for environmental monitoring and industrial process control. The XRF method was compared with a commercial scanning electron microscope with energy dispersive spectroscopy (SEM-EDS) for fly ash samples. Qualitative analysis and semi-quantitative analysis of Na, S, Cl, K and Cd in incineration fly ash were performed with these two similar techniques. One of the challenges of using XRF is the scattering background noise from the primary beam, which decreases the detection limit and the sensitivity of the measurement system. Hence, an X-ray beam filter was chosen to suppress the background noise for a specific element, Cr, in leachate. Numerical simulations and experiments were developed to find the proper filter material and thickness by calculating the X-ray fluorescence intensities and the signal-to-noise ratio. The developed system is capable of online monitoring of Cr levels, to certify that the concentration is below the threshold level in leachate. An XRF prototype was built and calibrated for underwater Hg analysis in maritime wet sediment using a radioisotope source. The presented results show that it is possible to detect Hg by K-shell emission thus enabling XRF analysis for sediment underwater.For non-homogeneous samples, an image revealing the elemental distribution can be achieved by micro-XRF (µ-XRF). XRF mapping of element distributions on a microscopic level was obtained by using scanning XRF microscopy and full-field XRF projection microscopy (FF-XRF). The spatial resolution of the scanning XRF imaging setup using an X-ray tube is in the order of 100 µm, but need to be further improved to measure the homogeneity of S on individual fiber level in pulp and paper industry. For the scanning technique, it is a tradeoff between resolution and measurement time. Another technique is FF-XRF imaging, and a setup was implemented using an energy resolving pixel detector and X-ray optics. The capabilities and limitations of using X-ray optics in XRF imaging systems have been identified. These microscopy measurements can guide further comprehensive environmental and industrial monitoring missions, utilizing elemental distribution information.
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| 19. |
- Andersson, Ewa, 1980-
(author)
-
Oberoendets praktik
- 2013
-
Doctoral thesis (other academic/artistic)abstract
- The Independent PracticeDuring the last hundred years, the music industry has evolved with the record labels playing a central role. However, many argue that this situation is about to change as record sales have decreased during the last ten years. This imminent change in the music industry will not only affect the multinational record labels, but also the independent record labels. As record sales have decreased during the last ten years, the number of members in the Swedish Independent Music Producers Association (SOM) has increased and the association now includes 300 independent record labels which are responsible for around 30 percent of the music being produced in Sweden. However, they can be considered a dominated group within the music industry, since they only have around 10 percent of the total market shares when it comes to selling figures. Considering the changes in record sales, the domination of the major record labels and the somewhat fascinating growth of independent actors during turbulent times, this thesis will study how the Swedish independent actors relate to the practices and ideals relevant in the daily work of running an independent record label. The practices studied in this thesis are the practice of work, the practice of recognition and the practice of content production.The purpose of this thesis is to analyse how independence is constructed among the members of SOM. The thesis is based on material collected in a web survey as well as seven interviews with representatives of indie labels. The web survey was distributed to all members of SOM, and the interviewed informants were selected by snowball sampling, using a locator to find informants. The survey material was analysed with cluster and variance analysis, while the interview material was analysed using content analysis – searching for themes connected to the practices. All material is understood through the theoretical frame of the field theory.The main results of the study are that there are different ways of relating to practices among the Swedish independent actors, and that these ways of relating are closely connected to their position within the field. There are common ways of relating to practices such as always promoting DIY, the importance of music and the need to resist the dominance of the major labels. However, the independent actors are not consistent in how these commonalities work in practice. For example, DIY is not applied if it is not economically necessary, and the need to resist the major labels is only apparent when the independent actor has a weaker position within the field. The more established an independent actor is within the field, the lesser resistant he is against the dominating structures of the music industry. As a result of a weakening resistance against the major labels, the independent actors turn to struggle each other.
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| 20. |
- Andersson, Erik, 1984-
(author)
-
PHYSIOLOGICAL AND BIOMECHANICAL FACTORS DETERMINING CROSS-COUNTRY SKIING PERFORMANCE
- 2016
-
Doctoral thesis (other academic/artistic)abstract
- Cross-country (c.c.) skiing is a complex sport discipline from both physiological and biomechanical perspectives, with varying course topographies that require different proportions of the involved sub-techniques to be utilised. A relatively new event in c.c. skiing is the sprint race, involving four separate heats, each lasting 2-4 min, with diverse demands from distance races associated with longer durations. Therefore, the overall aim of the current thesis has been to examine the biomechanical and physiological factors associated with sprint c.c. skiing performance through novel measurements conducted both in the field (Studies I-III) and the laboratory (Studies IV and V).In Study I sprint skiing velocities and sub-techniques were analysed with a differential global navigation satellite system in combination with video recording. In Studies II and III the effects of an increasing velocity (moderate, high and maximal) on the biomechanics of uphill classical skiing with the diagonal stride (DS) (Study II) and herringbone (HB) (Study III) sub-techniques were examined.In Study I the skiers completed the 1,425 m (2 x 712 m) sprint time trial (STT) in 207 s, at an average velocity of 24.8 km/h, with multiple technique transitions (range: 21-34) between skiing techniques (i.e., the different gears [G2-7]). A pacing strategy involving a fast start followed by a gradual slowing down (i.e., positive pacing) was employed as indicated by the 2.9% faster first than second lap. The slower second lap was primarily related to a slower (12.9%) uphill velocity with a shift from G3 towards a greater use of G2. The maximal oxygen uptake ( O2max) was related to the ability to maintain uphill skiing velocity and the fastest skiers used G3 to a greater extent than G2. In addition, maximal speed over short distances (50 and 20 m) with the G3 and double poling (DP) sub-techniques exerted an important impact on STT performance.Study II demonstrated that during uphill skiing (7.5°) with DS, skiers increased cycle rate and cycle length from moderate to high velocity, while cycle rate increased and cycle length decreased at maximal velocity. Absolute poling, gliding and kick times became gradually shorter with an elevated velocity. The rate of pole and leg force development increased with elevated velocity and the development of leg force in the normal direction was substantially faster during skiing on snow than previous findings for roller skiing, although the peak force was similar in both cases. The fastest skiers applied greater peak leg forces over shorter durations.Study III revealed that when employing the HB technique on a steep uphill slope (15°), the skiers positioned their skis laterally (“V” between 25 to 30°) and planted their poles at a slight lateral angle (8 to 12°), with most of the propulsive force being exerted on the inside forefoot. Of the total propulsive force, 77% was generated by the legs. The cycle rate increased across all three velocities (from 1.20 to 1.60 Hz), while cycle length only increased from moderate to high velocity (from 2.0 to 2.3 m). Finally, the magnitude and rate of leg force generation are important determinants of both DS and HB skiing performance, although the rate is more important in connection with DS, since this sub-technique involves gliding.In Studies IV and V skiers performed pre-tests for determination of gross efficiency (GE), O2max, and Vmax on a treadmill. The main performance test involved four self-paced STTs on a treadmill over a 1,300-m simulated course including three flat (1°) DP sections interspersed with two uphill (7°) DS sections.The modified GE method for estimating anaerobic energy production during skiing on varying terrain employed in Study IV revealed that the relative aerobic and anaerobic energy contributions were 82% and 18%, respectively, during the 232 s of skiing, with an accumulated oxygen (O2) deficit of 45 mL/kg. The STT performance time was largely explained by the GE (53%), followed by O2 (30%) and O2 deficit (15%). Therefore, training strategies designed to reduce energetic cost and improve GE should be examined in greater detail.In Study V metabolic responses and pacing strategies during the four successive STTs were investigated. The first and the last trials were the fastest (both 228 s) and were associated with both a substantially larger and a more rapid anaerobic energy supply, while the average O2 during all four STTs was similar. The individual variation in STT performance was explained primarily (69%) by the variation in O2 deficit. Furthermore, positive pacing was employed throughout all the STTs, but the pacing strategy became more even after the first trial. In addition, considerably higher (~ 30%) metabolic rates were generated on the uphill than on the flat sections of the course, reflecting an irregular production of anaerobic energy. Altogether, a fast start appears important for STT performance and high work rates during uphill skiing may exert a more pronounced impact on skiing performance outdoors, due to the reduction in velocity fluctuations and thereby overall air-drag.
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| 21. |
- Andersson, Henrik, 1975-
(author)
-
Position Sensitive Detectors : Device Technology and Applications in Spectroscopy
- 2008
-
Doctoral thesis (other academic/artistic)abstract
- This thesis deals with the development, processing and characterization of position sensitive detectors and, in addition, to the development of compact and cost effective spectrometers. Position sensitive detectors are used to measure, with great accuracy and speed, the position of a light spot incident on the surface. Their main use is for triangulation, displacement and vibration measurements. A type of position sensitive detector based on the MOS principle and using optically transparent indium tin oxide as a gate contact has been developed. This type of detector utilizes the MOS principle where an induced channel forms beneath the gate oxide in the surface of the Silicon substrate. One and two dimensional detectors have both been fabricated and characterized. The first measurements showed that the linearity did not fulfil expectations and it was suspected that stress induced by the gate contact could be the reason for the seemingly high nonlinearity. Further investigations into both the p-n junction and the MOS type position sensitive detectors lead to the conclusion that the indium tin oxide gate is responsible for inducing a substantial stress in the surface of the detector, thus giving rise to increased position nonlinearity. The heat treatment step which was conducted was determined to be critical as either a too short or too long heat treatment resulted in stress in the gate and channel leading to position nonlinearity. If a correctly timed heat treatment is performed then the detector’s linearity is in parity with the best commercial position sensitive detectors. In addition, the development of very small, compact and cost effective spectrometers has been performed with the aim of constructing devices for use in the process industry. The development of a wedge shaped array of Fabry-Perot interferometers that can be mounted directly on top of a detector makes it possible to construct a very compact spectrometer using the minimum amount of optics. This wedge interferometer has been evaluated by means of array pixel detectors and position sensitive detectors for both the infrared and the visible wavelength ranges. When used with a position sensitive detector it is necessary to use a slit to record the intensity of the interferogram for many points over the detector, equivalent to pixels on an array detector. Usually the use of moving parts in a spectrometer will impose the use of high precision scanning mechanisms and calibration. By using a position sensitive detector for the interferogram readout both the position and the intensity are known for every measurement point and thus the demands placed on the scanning system are minimized.
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| 22. |
- Andreassen Devik, Siri
(author)
-
Hjemmesykepleie til eldre som bor på bygda med uhelbredelig kreft
- 2016
-
Doctoral thesis (other academic/artistic)abstract
- The need to deliver high-quality palliative homecare has been underscored in current professional guidelines and demands for efficacy, as well as in the preferences of patients and their families. Indeed, demographic changes and an increased risk of cancer among older people pose challenges to the home healthcare settings in Norway and the rest of the world. Yet, little is known about how older persons experience living with incurable cancer and how palliative home nursing care may increase their quality of life. Moreover, few studies have focused on rural contexts or explored such settings can influence the delivery and outcome of care. In rural contexts, long distances and limited health-related human resources challenge the provision of specialised services, and palliative patients living in rural municipalities most often receive services from district nurses without special training in oncological or palliative care. The aim of this thesis was thus to explore experiences with, and meanings of, rural home nursing care among older persons living with incurable cancer. The thesis consists of five studies, all with qualitative designs, and performed in rural municipalities.Study I was designed as a case study involving individual interviews and observations to explore how older persons diagnosed with incurable cancer and living alone have experienced daily life while commuting for policlinic palliative chemotherapy. By extension, the aim of Study II, conducted as a secondary analysis of material collected in study I, was to illuminate and interpret the meanings of the lived experiences of the participants in that study. By contrast, Study III used individual interviews to illuminate and interpret the meaning of the lived experience of older persons with incurable cancer, yet who have received home nursing care. Meanwhile, Study IV entailed individual interviews with nurses working in home nursing care. Its aim was to illuminate and interpret the meaning of nurses' lived experiences among severely ill patients in their homes. Lastly, Study V involved individual interviews with bereaved family members; its aim was to explore their perceptions of suffering in older persons receiving palliative home nursing care during their final phase of life. The findings of Study I showed that older persons interviewed hovered between hope and fear, experienced stressful commutes, and were constantly exhausted. Experiences with long, tiring taxi trips, of having few supportive people nearby, and of being offered hardly any local healthcare services made these persons highly vulnerable. Nevertheless, their demands were few, and they rarely complained. The findings of Study II showed a complex, yet comprehensive situation in which physical symptoms and emotions had become entangled. Four themes were found: enduring by keeping hope alive, becoming aware of being one one's own, living up to expectations of being a good patient, and being at risk of losing identity and value. Suffering related to care, or the lack therefore, was the most striking discovery, and the older persons seemed to endure by keeping hope alive. Besides hoping for survival, their hopes also included a desire to be recognised and treated with respect, though such often seemed to go unnoticed. The findings of Study III revealed three themes: being content with what one gets, falling into place, and losing one's place. The phrase picking up the pieces was found useful for summing up the meaning of one's lived experience. In that sense, the three themes referred to how the pieces symbolized the remaining parts of life or services available in their environment and how the older persons might see themselves as pieces in a puzzle. Participants exhibited strong place attachment, involving physical insideness, social insideness, and autobiographical insideness, which suggested that the rural context might provide and advantageous healthcare environment. Interestingly, nurses' personal engagement and willingness to be involved in caring relationship appeared to be more important than any special competence or technical skills. The findings of Study IV showed that patients' expressions left impressions that caused emotional waves in the nurses. Four themes were found: being open for the presence of the Other, being satisfied, being frustrated, and being ambivalent. Understanding and balancing this emotional dimension in care seemed to cause confusion and distress for the nurses, and realizing how their feelings might prompt either generosity or aloofness towards the patient was upsetting. Thatinterpretation suggested confusion regarding what it means to be a professional nurse.Lastly, the findings of Study V showed that bereaved family members perceived suffering related to the illness, to the care, and to the life of their ill relatives during their final phase of life. Well-being emerged as having significant, contrasting elements. Well-being related to other people, to the home, and to activity, in all of which the essence referred to a state of dwelling-mobility. The findings suggested that nurses in this context need to seek out patients' and their families members' experiences with comfort and with disturbance. Nursing and palliative care that become purely disease- and symptom-focused can end with all parties' giving up and divert attention from social and cultural factors that may contribute to well-being when cure is not the goal.The findings of this thesis could alter some current knowledge in the field. From a patient perspective, the rural context is not necessarily disadvantaged, care is not necessarily caring, and the alleviation of suffering and cultivation of wellbeing are not necessarily two sides of the same coin. Home nursing care is often seen as a precondition for staying at home. Working in patients' homes allows nurses to witness and become involved in each patient's unique situation. However, impressions of patients' expressions awake feelings in nurses that have the power to bring about caring actions. At the same time, the fear of being unprofessional or unable to deliver proper care bothers nurses and might threaten the closeness that patients desire. Home nursing is care organized in a system in which services are predefined, apportioned, and bound to specific procedures, and the holistic ideals of the palliative care philosophy are often not within the framework of the system in which district nurses work.
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| 23. |
- Andres, Britta, 1986-
(author)
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Low-Cost, Environmentally Friendly Electric Double-Layer Capacitors : Concept, Materials and Production
- 2017
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Doctoral thesis (other academic/artistic)abstract
- Today’s society is currently performing an exit from fossilfuel energy sources. The change to sustainable alternativesrequires inexpensive and environmentally friendly energy storagedevices. However, most current devices contain expensive,rare or toxic materials. These materials must be replaced bylow-cost, abundant, nontoxic components.In this thesis, I suggest the production of paper-based electricdouble-layer capacitors (EDLCs) to meet the demand oflow-cost energy storage devices that provide high power density.To fulfill the requirements of sustainable and environmentallyfriendly devices, production of EDLCs that consist of paper,graphite and saltwater is proposed. Paper can be used as aseparator between the electrodes and as a substrate for theelectrodes. Graphite is suited for use as an active material in theelectrodes, and saltwater can be employed as an electrolyte.Westudied and developed different methods for the productionof nanographite and graphene from graphite. Composites containingthese materials and similar advanced carbon materialshave been tested as electrode materials in EDLCs. I suggest theuse of cellulose nanofibers (CNFs) or microfibrillated cellulose(MFC) as a binder in the electrodes. In addition to improvedmechanical stability, the nanocellulose improved the stabilityof graphite dispersions and the electrical performance of theelectrodes. The influence of the cellulose quality on the electricalproperties of the electrodes and EDLCs was investigated.The results showed that the finest nanocellulose quality is notthe best choice for EDLC electrodes; MFC is recommended forthis application instead. The results also demonstrated thatthe capacitance of EDLCs can be increased if the electrodemasses are adjusted according to the size of the electrolyte ions.Moreover, we investigated the issue of high contact resistancesat the interface between porous carbon electrodes and metalcurrent collectors. To reduce the contact resistance, graphitefoil can be used as a current collector instead of metal foils.Using the suggested low-cost materials, production methodsand conceptual improvements, it is possible to reduce the material costs by more than 90% in comparison with commercialunits. This confirms that paper-based EDLCs are apromising alternative to conventional EDLCs. Our findings andadditional research can be expected to substantially supportthe design and commercialization of sustainable EDLCs andother green energy technologies.
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| 24. |
- Andresen, Edith
(author)
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Dressed for success : designing and managing regional strategic networks
- 2011
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Doctoral thesis (other academic/artistic)abstract
- Inter-organizational network initiatives such as regional strategic networks (RSNs) are often used by firms and public agencies to support regional development and competitiveness. RSNs are designed networks managed by a hub and financed by public or private means. RSN management is complex as members are autonomous and initially often loosely connected. The effects of RSNs on regional development are disputed as engineered relationship development may interfere with ongoing business relationships. Despite this, vast public funds are being invested in collaborative initiatives. Identifying factors affecting RSN performance will provide a better basis for evaluating and managing such initiatives.Based on concepts such as actors, resources, and activities findings are reported from longitudinal case-studies built on interviews with 68 members and hubs in four RSNs. Data were also collected through participant observation, conversations, archival data and emails. Findings indicate that factors such as evaluation criteria, member composition, relationships, location, goals, the hub, physical and human resources, knowledge sharing and development, resources, policies and norms, social activities, and communication exert an impact on entrepreneurship and cooperation.The first paper focuses on factors such as actor composition, actor goals, number of actors, and activities facilitating relationship development and commitment. The second paper identifies a framework of seven tasks to be performed by the hub. The effects on development of preferences and atmosphere are dealt with in the third paper. Effects of cooperation between public/private sector and universities are addressed in the fourth paper, and entrepreneurial processes in network contexts are analyzed in the fifth one.The important management role of the hub is emphasized as is carefully considered member composition. Relationships and commitment are found to be crucial. These factors are not covered by national and regional performance criteria. They merit a place of their own.
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| 25. |
- Aranda, Jesus Javier Lechuga
(author)
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Towards Self-Powered Devices Via Pressure Fluctuation Energy Harvesters
- 2021
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Doctoral thesis (other academic/artistic)abstract
- The growing interest in the Internet of Things has created a need for wireless sensing systems for industrial and consumer applications. In hydraulic systems, a widely used method of power transmission in industry, wireless condition monitoring can lead to reduced maintenance costs and increase the capacity for sensor deployment. A major problem with the adoption of wireless sensors is the battery dependence of current technologies. Energy harvesting from pressure fluctuations in hydraulic systems can serve as an alternative power supply and enable self-powered devices. Energy harvesting from pressure fluctuations is the process of converting small pressure fluctuations in hydraulic fluid into a regulated energy supply to power low power electronics. Previous studies have shown the feasibility of pressure fluctuation harvesting. However, for the development of self-powered sensor systems, the methods and techniques for converting pressure fluctuations into electrical energy should be further investigated.This thesis explores the methods, limitations, opportunities and trade-offs involved in the development of pressure fluctuation energy harvesters in the context of self-powered wireless devices. The focus is on exploring and characterizing the various mechanisms required to convert pressure fluctuations into electrical energy. In this work, an energy harvesting device consisting of a fluid-to-mechanical interface, an acoustic resonator, a piezoelectric stack, and an interface circuit is proposed and evaluated. Simulations and experimental analysis were used to analyse these different components for excitation relevant to hydraulic motors.The results of this work provide new insights into the development of power supplies for self-powered sensors for hydraulic systems using pressure fluctuation energy harvesters. It is shown that with the introduction of the space coiling resonator for pressure fluctuation amplification and a detailed analysis of the fluid interface and power conditioning circuits, the understanding of the design and optimization of efficient pressure fluctuation energy harvesters is further advanced.
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