Estimation of Sparsity via Simple Measurements

We consider several related problems of estimating the 'sparsity' or number of nonzero elements $d$ in a length $n$ vector $\mathbf{x}$ by observing only $\mathbf{b} = M \odot \mathbf{x}$, where $M$ is a predesigned test matrix independent of $\mathbf{x}$, and the operation $\odot$ varies between problems. We aim to provide a $\Delta$-approximation of sparsity for some constant $\Delta$ with a minimal number of measurements (rows of $M$). This framework generalizes multiple problems, such as estimation of sparsity in group testing and compressed sensing. We use techniques from coding theory as well as probabilistic methods to show that $O(D \log D \log n)$ rows are sufficient when the operation $\odot$ is logical OR (i.e., group testing), and nearly this many are necessary, where $D$ is a known upper bound on $d$. When instead the operation $\odot$ is multiplication over $\mathbb{R}$ or a finite field $\mathbb{F}_q$, we show that respectively $\Theta(D)$ and $\Theta(D \log_q \frac{n}{D})$ measurements are necessary and sufficient.Comment: 13 pages; shortened version presented at ISIT 201

Deep Dive into Sustainability Assessment Methods Cradle-to-Grave: Detriment or Benefit?

The Construction Industry has been portrayed as a culprit in the global pursuit of sustainable development due to the vast resources that the industry exploits and the chemicals and pollutants it emits. It is commonly estimated that the construction industry utilizes about 30- 40% of the global natural resources. An important mitigator in the quest for a more sustainable construction industry is Sustainability Assessment Methods (SAMs) or Green Building Rating Systems. SAMs were first introduced in the early 2000s and has since gained momentum worldwide. It is now predicted to become a mainstream practice for large construction projects. Different studies show that capital costs may increase short-term, compared to a ‘ordinary’ project. However, certifying can lead to 6-30% in long-term capital savings. On the other hand, actors in the industry sometimes perceive certain criteria or sustainability indicators (SIs) belonging to SAMs to be ill-considered. Do these SIs still contribute toward sustainability, are they beneficial or detrimental to the project? This Master Thesis investigates three SAMs, BREEAM, LEED and Miljöbyggnad along with the ecolabel Nordic Swan and service SundaHus. What are their sustainability indicators grounded on? Are they aligned with the United Nations Sustainable Development Goals (SDGs) and does a certified building equal a sustainable one? Two case studies are included in the Thesis. These investigate whether or not energy saving measures from two different kinds of heat exchangers are more sustainable then procuring only green power, such as BraMiljöval, in a specific real-life project. The case studies evaluate the possible energy savings and what Global Warming Potential (GWP) they have and compare which solution has the lowest GWP. The conclusion is that certified buildings do not equal sustainable buildings, but it is likely that the CO2 footprint of a certified building will be less than that of a non-certified. Since SAMs are not adapted per project, in certain scenarios some SIs become a detriment rather than a benefit, but in a larger sense are still beneficial. Additionally, SAMs do contribute toward the UNs SDGs and Sweden’s Environmental Quality Goal

Studies on hip fracture patients : effects of nutrition and rehabilitation

Hip fracture in the elderly is a serious condition associated with increased mortality. Survivors experience an increase in morbidity and disability that affect their independence and quality of life; the outcome for patients with dementia is particularly poor. Many hip fracture patients have signs of malnutrition already on admission and this patient group has been shown to have a lower body mass index (BMI) than aged-matched controls. A catabolic state develops following hip fracture, characterized by loss of bone mineral density (BMD) and muscle mass. The combination of generalized loss of muscle mass, muscle strength and/or physical performance is known as sarcopenia, which impacts functionality and health- related quality of life. This thesis has three major aims: 1) to study the possible association between BMI, a potentially modifiable factor, and one-year mortality, as well as the ability to return to independent living following hip fracture; 2) to evaluate the effect of nutritional supplementation on bone mineral density (BMD), body composition, muscle strength and health-related quality of life (HRQoL) following hip fracture; and 3) to investigate factors of importance for preservation of ambulatory function and activities of daily living (ADL) following hip fracture in patients with cognitive impairment. Study I: A prospective study of 843 elderly patients with hip fracture, without severe cognitive impairment, who came from an independent living situation at the time of admission. The results show that overweight was associated with increased one-year survival and a greater likelihood of independent living one year post-fracture. Study II: A randomized controlled study in which 79 patients with hip fracture were randomized to one of three treatment groups. Six months of postoperative treatment with protein and energy-rich supplementation combined with orally administered bisphosphonate, calcium and vitamin D were shown to have a small additive effect on bone mineral density compared with bisphosphonate and calcium alone. Study III: A randomized controlled study of the same population as in study II. Postoperative treatment with protein and energy-rich supplementation did not prevent loss of lean mass following hip fracture. However, trends toward improved handgrip strength and HRQoL were observed following nutritional supplementation. Study IV: A prospective study of 246 patients with femoral neck fracture and cognitive impairment, but ambulant prior to fracture. In addition to ambulatory and ADL function prior to fracture, the results showed that discharge to rehabilitation facilities was associated with preserved ambulatory function and ADL skills at the 4-and 12 month follow-ups

To move ahead - the extension of a life-world

This licentiate thesis is a monography complemented with one published article: “Interactive Design – the desire for autonomous upright mobility: A longitudinal case study, Technology and Disability 19 (2007) 213-224”. My hope is that the combination of the monographic part (with its phenomenological tone, personified and situated), and the more unbarked “Technology and Disability” article (with its orientation towards the general rather than the personal aspects) will contribute to dialogues on different scientifical approaches. The overall purpose of this thesis is to develop new knowledge on child development under the conditions of SMA II. As I use a life-world phenomenological approach my first quest is to highlight and make explicit what appeared in Hanna’s life-world and how these experiences have contributed to her overall development. I also want to put forward how Hanna’s motility and mobility were supported, guided by what she expressed and strived for, in order to promote a healthy physical, psychological and social development. A special focus is on independent locomotion and how this was accomplished for Hanna. By using technology in a new way it was possible to enhance Hanna’s access to the world through the medium of her lived body, thus changing her life-world by widening her life-world horizon. The second quest of this licentiate thesis is to make this journey explicit

Investigating metabolic dysfunction and arrhythmogenesis in an early-onset atrial fibrillation patient cohort

Despite the prevalence of atrial fibrillation (AF) and the burden it places on health care systems, there remains much that is unknown regarding heritable factors influencing its development and progression. In this study, I investigated whole-exome sequencing (WES) data from a cohort of patients presenting with early-onset AF to explore the role that metabolic dysfunction might play in contributing to disease onset. I curated a metabolism-related gene panel and, following in silico prediction of variant pathogenicity, performed gene-level burden testing using reference data from the Genome Aggregation Database (gnomAD) and the human mitochondrial genome database MITOMAP. I further explored genes associating with AF in the UK Biobank data set, and discovered associations with several AF comorbidities including diabetes, hypertension, and stroke

Yes we can - bidrage til at skabe ny vækst!

I DEFF undrer man sig højlydt over den skepsis, som forskningsbibliotekerne udviser over for den seneste DEFF-strategi. Hvorfor skulle bibliotekerne ikke kunne understøtte virksomhederne med support og services

Debugging the future: quality of life, academic success and student acceptability of assistive technology

Research has shown that integration of Assistive Technology (AT) in the educational environment is minimal but can offer life-changing benefits. My study explores the obstacles of AT and the relationship between acceptability of AT and student quality of life as well as individual self-reported academic success. I surveyed two existing groups of students at a regional comprehensive university. The first group is receiving assistance through instruction and tutoring services. The second group is receiving support to pursue future doctoral studies. Participants provided self-report of their academic strengths and challenges, acceptability of AT, and quality of life. I offered participants multiple opportunities to learn about and engage in different types of AT. Types of AT offered included: Read and Write Gold 10 (2013 Texthelp Ltd, 2013) Grammarly (Grammarly, Inc., 2013), and Dragon Naturally Speaking (Nuance Communications, Inc., 2012-2013). I predicted that higher self-reported academic challenges would increase acceptability towards AT and decrease self-reported quality of life. I also predicted that students with higher GPA would be less accepting to AT interventions. I found that there was no correlation between GPA and acceptability of AT or self-reported academic struggles and acceptability of AT. I did however find a significant negative correlation between quality of life and self-reported academic challenges

Algorithms to Exploit Data Sparsity

While data in the real world is very high-dimensional, it generally has some underlying structure; for instance, if we think of an image as a set of pixels with associated color values, most possible settings of color values correspond to something more like random noise than what we typically think of as a picture. With an appropriate transformation of basis, this underlying structure can often be converted into sparsity in data, giving an equivalent representation of the data where the magnitude is large in only a few directions relative to the ambient dimension. This motivates a variety of theoretical questions around designing algorithms that can exploit this data sparsity to achieve better performance than what would be possible naively, and in this thesis we tackle several such questions.We first examine the question of simply approximating the level of sparsity of a signal under several different measurement models, a natural first step if the sparsity is to be exploited by other algorithms. Second, we look at a particular sparse signal recovery problem called nonadaptive probabilistic group testing, and investigate the question of exactly how sparse the signal needs to be before the methods used for recovering sparse signals outperform those used for non-sparse signals. Third, we prove novel upper bounds on the number of measurements needed to recover a sparse signal in the universal one-bit compressed sensing model of sparse signal recovery. Fourth, we give some approximations of an information-theoretic quantity called the index coding rate of a network modeled by a graph, in the special case that the graph is sparse or otherwise highly structured. For each of the problems considered, we also discuss some remaining open questions and conjectures, as well as possible directions towards their solutions

Performances at an AIDS Memorial Quilt Display: An Ethnographic Study of Rehearsal

Several tentative research questions posed early in the study focused on the audience. The study of audience was later abandoned because it would not have been feasible for one researcher to conduct analyses of audiences while also observing performers. A study of these audiences would have been interesting because these were not a typical audience coming to a theatre for entertainment. These audiences were emotionally tied to the topic of the texts. Most of the audience members were highly knowledgeable about AIDS and related issues. The only audience analyses in this study were the directors\u27 and performers\u27 impressions of audience response obtained through interviews and the researcher\u27s own observations. The questions of the study became: what behaviors occurred during rehearsals, what were the performers\u27 initial impressions of the script, did these impressions change over time, how much initial knowledge did the performers have about AIDS and the AIDS Memorial Quilt, how well did the performers function as a group, and what ~ were the performers reactions to and perceptions of events at the quilt display

Share-using in Industristaden : a study of preschool courtyards and parks in an urban district

Ett vanligt förekommande problem i täta städer är att förskolegårdar är små och innehåller stora brister (Ritzén 2018). En lösning till detta problem skulle kunna vara samnyttjande där allmänna parker kan komplettera gården vid utevistelse. För att samnyttjande ska vara en fungerande strategi behöver även parkerna se till barnens behov. Barnens behov har fått en ny prioritering med Barnkonventionen som svensk lag sedan 2020 (Barnombudsmannen 2021). Syftet med arbetet är därför att utreda om Uppsala kommun ser till barnrättsperspektivet och Barnkonventionen när det gäller barns utemiljöer i den täta staden. Syftet är brett och därför valdes samnyttjande i parker av förskolegårdar som ett avgränsat undersökningsområde. För att ytterligare begränsa studien, undersöks endast hur samnyttjande skulle fungera i Industristaden, Uppsala. Tre förskolor, en park och en lekplats analyserades med platsanalyser utifrån deras lekvärden. Detta genomfördes för att besvara frågeställningen: “Kan parkerna i Industristaden komplettera förskolans behov av utemiljöer och lekvärden när förskolegården är för liten?”. Dokumentstudier användes för att komplettera platsanalyserna med relevant information såsom barnens behov, Uppsala kommuns riktlinjer, planer för Industristaden och artiklar från Barnkonventionen. Resultaten visar att samnyttjande i Industristaden inte är en strategi som ser till barnens mångsidiga behov, eftersom parkerna endast delvis kunde komplettera förskolegårdarna. Både parkerna och förskolegårdarna i Industristaden saknar varierande miljöer med naturinslag, där barn kan påverka sin omgivning. Om parkerna i området innehöll efterfrågade kvaliteter, hade samnyttjande kunnat bidra till barnens hälsa och utveckling, särskilt eftersom barnen är begränsade till sina små förskolegårdar. Därför behöver det ske större satsningar på utemiljöer för barnen i området för barnens hälsa, välmående och utveckling. Avslutningsvis behöver Uppsala kommun göra mer för barnen i Industristaden om barnrättsperspektivet och barnkonventionen ska uppehållas.A common problem in urban cities is that preschool’s outdoor environments are small and lacking in qualities (Ritzén 2018). One solution to this problem could be share-using public parks to complement the preschool courtyard. However, for share-using to be a functioning strategy the parks are required to meet the needs of children. The needs of children have since 2020 gained a new priority due to the Convention of the Rights of the Child becoming part of Swedish law (Barnombudsmannen 2021). Therefore, the purpose of the work is to investigate whether Uppsala municipality considers the perspective of children's rights and the Convention on the Rights of the Child when it comes to children's outdoor environments in the urban city. Since the aim of the study is broad the focus will lie on the share-using of parks by preschools. To even future limit the scope of the study only the share-using in Industristaden, Uppsala will be analyzed. Three preschools, one park and one playground were investigated with site-analyses to find their respective playvalues. This was done to answer the question: “Can the parks in Industristaden complement the preschool's needs for outdoor environment and playvalues when the courtyard is too small?”. Document studies were used to complement the site-analyses with relevant information such as the children's needs, Uppsala Municipality's guidelines, plans for Industrstaden and articles from the Convention on the Rights of the Child. The results show that share-using in Industristaden is not a strategy that meets the varied needs of the children, since the parks can only partially complement the preschool courtyards. Both the parks and preschool yards in Industristaden lack varied environments with natural elements, where children can influence their surroundings. If the parks in the area included the sought after qualities, then share-using could have contributed to children's health and continued development. Especially since the children are confined to their small preschool courtyards. Therefore, there needs to be a greater investment in outdoor environments for children in the area to contribute to their health, wellbeing and development. In conclusion Uppsala Municipality needs to do more for the children in Industristaden to maintain the child rights perspective and the Convention on the Rights of the Child