Development of technical and methodological support has been identified as a key area for future research and development within the search and rescue (SAR) of missing persons in Sweden. Previous studies have demonstrated the feasibility of using Wi-Fi signals to locate a missing person, and also developed hardware and software for SAR systems based around Unmanned Aerial Vehicles (UAV). This thesis empirically studies the actual transmission behaviour of three non-connected smartphones over Wi-Fi and Bluetooth Low Energy (BLE), under the assumption that a missing person could be carrying a smartphone with them. Furthermore, the thesis studies the range of relatively low-cost off-the-shelf Wi-Fi and BLE devices in a “best-case” scenario with free line-of-sight and a slightly elevated transmitter. Finally, the thesis studies how antennas and other factors impact range. The results show that all of the tested smartphones transmit so called Wi-Fi probe packets when Wi-Fi is enabled. Though, these probes are, in most cases, transmitted during short events separated by intervals of 5 to 9 minutes, depending on the smartphone. Furthermore, in most cases only a few packets are transmitted in each event. The interval lengths and scarce packets imply significant limitations to the usability of Wi-Fi in SAR. BLE broadcast transmissions, on the other hand, require that some kind of advertising service is enabled, but are transmitted at least every 10.5 seconds, due to the strict regulation in the Bluetooth standard. This was also demonstrated with the studied iPhone that continuously transmitted BLE packets every two seconds. Roughly 60 % of the smartphones in use in Sweden today are Apple devices, thus a significant portion of all the smartphones in use are likely to be detectable via BLE within brief time intervals. In the tested “best-case” scenario with free line-of-sight and a slightly elevated transmitter, at least 80 % of the transmitted Wi-Fi probes are detected up to 500-600 meters with a maximum range, with sparsely detected packets, of up to about 700 meters. Correspondingly, at least 80 % of the BLE advertisements are detected up to 60-110 meters with occasional packets detected up to a maximum range of approximately 210 meters. However, the ranges for both Wi-Fi and BLE are highly dependent on the receiving device. In addition to the receiver device and standard, it is found that the transmission power and antenna directivity of the transmitter have a potentially substantial impact on the range with a possible combined difference in directed transmitted power of up to 49 dB. This corresponds to the difference between a strong signal and no detected signal at all. In summary, there are clear differences between the properties of BLE and Wi-Fi, both in terms of range and how different devices transmit broadcast packets (transmission behaviour), resulting in both having advantages and disadvantages in SAR applications. There are also a number of factors on the transmitter and receiver devices that could have considerable impact on the possibility of detecting a device. Concludingly, both BLE and Wi-Fi could fill a role in SAR of missing persons, but both also have major drawbacks that are severely limiting their possible use. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

I dagens samhälle används Bluetooth Low Energy (BLE) alltmer, särskilt inom IoT-enheter (Internet of Things). Detta ökar behovet av säker kommunikation och att identifiera samt åtgärda potentiella sårbarheter. Problemet som denna studie adresserar är risken för passiv avlyssning och säkerhetsbrister i BLE-kommunikation, vilket kan leda till datamissbruk och integritetsintrång. Detta arbete fokuserar på att undersöka säkerheten inom BLE-signalering och presenterar även en praktisk laboration för att öka kunskapsnivån inom analys och hantering av blåtandstrafik. Säkerhetsbrister utvärderas genom att analysera trafiken mellan BLE-enheter, med specifik fokus på passiv avlyssning och de potentiella riskerna med detta. Genom praktiska experiment med tre olika blåtandsenheter, inklusive smarta LED-lister och ett smart hopprep, undersöktes hur signaleringsdata kan extraheras och missbrukas. Resultaten visar att även om nyare versioner av blåtand tillhandahåller förbättrade säkerhetsmekanismer, utnyttjas dessa inte alltid korrekt i produkter med lägre säkerhetskrav. Arbetet ger insikter i hur befintliga säkerhetsmekanismer kan förbättras och betonar vikten av kontinuerliga säkerhetsuppdateringar från tillverkare. / Today, Bluetooth Low Energy (BLE) is increasingly used, particularly in IoT devices (Internet of Things). This increase raises the need for secure communication and identifying as well as addressing potential vulnerabilities. The problem addressed by this study is the risk of passive eavesdropping and security flaws in BLE communication, which can lead to data misuse and privacy breaches. This work focuses on examining the security of BLE signaling and also presents a practical lab to enhance knowledge in analyzing and managing Bluetooth traffic. Security vulnerabilities are evaluated by analyzing the traffic between BLE devices, with a specific focus on passive eavesdropping and its potential risks. Through practical experiments with three different Bluetooth devices, including smart LED strips and a smart jump rope, the study investigated how signaling data can be extracted and misused. The results show that although newer versions of Bluetooth provide improved security mechanisms, these are not always correctly implemented in products with lower security requirements. The study provides insights into how existing security mechanisms can be improved and emphasizes the importance of continuous security updates from manufacturers.

Low-energy buildings have, in recent years, gained attention and moved towards a large-scale introduction in the residential sector. During this process, national and international criteria for energy use in buildings have become stricter and the European Union has through the Energy Performance of Buildings Directive imposed on member states to adapt their building regulations for ‘Nearly Zero Energy Buildings’, which by 2021 should be standard for new buildings. With a primary focus on new terraced and detached houses, this thesis analyses how the concept of low-energy buildings may be further developed to reduce the energy use in the residential sector. The main attention is on the technical performance in terms of indoor climate and heat consumption as well as on the market diffusion of low-energy buildings into the housing market. A multidisciplinary approach is applied, which here means that the concept of low-energy buildings is investigated from different perspectives as well as on different system levels. The thesis thus encompasses methods from both engineering and social sciences and approaches the studied areas through literature surveys, interviews, assessments and simulations. The thesis reveals how an increased process integration of the building’s energy system can improve the thermal comfort in low-energy buildings. Moreover, it makes use of learning algorithms – in this case artificial neural networks – to study how the heat consumption can be predicted in a low-energy building in the Swedish climate. The thesis further focuses on the low-energy building as an element in our society and it provides a market diffusion analysis to gain understanding of the contextualisation process. In addition, it suggests possible approaches to increase the market share of low-energy buildings. / <p>QC 20140321</p>

Résumé : Lors de l’utilisation de la radiation pour le diagnostic et le traitement du cancer, l’ADN est une cible importante due à son rôle dans la division cellulaire. La radiation y dépose de l’énergie par production abondante (10[indice supérieur 5] e[indice supérieur −]/MeV) d’électrons de basse énergie (EBE) (<50 eV) menant à la production de radicaux et à la dissociation de molécules. Une meilleure compréhension de ces phénomènes physico-chimiques mènera au développement de nouvelles stratégies en radioprotection et en radiothérapie. Il est primordial d’identifier et de quantifier ces dommages initiaux. Suite à des résultats obtenus par des expériences récentes (Li et al., 2010) sur des couches minces d’ADN irradiées par des EBE dans le vide, nous suggérons que certains produits désorbent en quantité significative. Nous proposons une méthode pour mesurer cette perte de matière en utilisant une balance à quartz pour mesurer in situ les changements de masse totale. Ce mémoire présentera la conception et la construction de l’appareil ainsi que les résultats d’irradiation de la thymine et de la thymidine. À 25 ◦ C, le taux de perte de masse spontanée des échantillons joue un rôle important pour les petites molécules comme la thymine (126 uma). L’irradiation augmente d’abord ce taux qui diminue d’un facteur 5 à 15 après une exposition prolongée, signe de modifications notables de l’échantillon. Pour des molécules plus imposantes comme la thymidine (242 uma), il n’y a pas de désorption spontanée et le taux de désorption induite par des électrons de 50 eV est de 0,4 ± 0,1 uma/e[indice supérieur -]. Cette méthode, nécessaire à la calibration d’autres expériences réalisées par HPLC et spectrométrie de masse, permet de compléter la quantificationdes fragments, qui peuvent aussi être l’origine de lésions subséquentes. / Abstract : DNA is the principle target of radiotherapy (RT) due to its crucial role in cellular growth and function. Ionizing radiation (IR) delivers its energy into the cell and its nucleus via sequential ionization events that produce many low-energy electrons (LEE)(10[superscript 5]e[superscript −] per MeV) which drive subsequent molecular dissociations and the formation of radicals and other reactive species. Since a better understanding of these mechanisms is needed to develop new strategies for radioprotection and RT, it is essential to identify and to quantify the initial damage induced by IR. Recent chromatographic (HPLC) analysis of short oligonucleotide irradiated with LEE in vacuo (Li et al., 2010) revealed that only ∼30 % of the loss of intact molecules could be explained by the formation of identifiable radiation products. We hypothesize that electron stimulated desorption (ESD) may account for some of the unexplained loss of the missing molecules. Here we propose a new experimental method to quantify this loss using a quartz crystal microbalance to measure in situ the total mass change due to ESD. This thesis describes the design and the construction of the novel apparatus and presents results for LEE irradiated thymine (thy) and thymidine (dT). We find that at 25 ◦ C, the thermal-induced mass loss is important for small molecules such as thy (126 amu). Upon irradiation at 50 eV, the rate of mass loss initially increases, but then decreased by factors between 5 and 15 indicating structural changes occurring at the sample surface. For larger molecules such as dT (242 amu), there is no thermal evaporation at 25 ◦ C and the LEE induced rate of desorption at 50 eV is 0.4 ± 0.1 amu/e[superscript -]. This work is needed to calibrate HPLC and mass spectrometry experiments allowing us to quantify the fragment species produced by LEE that are expected to induce further and biologically significant damage.

This thesis presents an investigation into the viability of Low Energy Earth Pipe Cooling Technology in providing thermal comfort in Malaysia. The demand for air-conditioning in buildings in Malaysia affects the country escalating energy consumption. Therefore, this investigation was intended to seek for a passive cooling alternative to air-conditioning. By reducing the air-conditioning demand, there would be a higher chance of Malaysia government to achieve their aim in reducing CO2 emissions to 40 per cent by the year 2020, compared to 2005 levels. The passive technology, where the ground was used as a heat sink to produce cooler air, has not been investigated systematically in hot and humid countries. In this work, air and soil temperatures were measured on a test site in Kuala Lumpur. At 1m underground, the result is most significant, where the soil temperature are 6oC and 9oC lower than the maximum ambient temperature during wet and dry season, respectively. Polyethylene pipes were buried around 0.5m, 1.0m and 1.5m underground and temperature drop between inlet and outlet were compared. A significant temperature drop was found in these pipes: up to 6.4oC and 6.9oC depending on the season of the year. The results have shown the potential of Earth Pipe in providing low energy cooling in Malaysia. A parametric study on the same experiment was carried out using Energy Plus programme. Energy Plus data agreed with the field work data and therefore, this confirms Energy Plus is reliable to investigate Earth Pipe Cooling in Malaysia. Furthermore, thermal comfort of air at the Earth Pipe outlet was analyzed and the result has shown that the outlet air is within the envelope of thermal comfort conditions for hot/humid countries

published_or_final_version / abstract / Physics / Doctoral / Doctor of Philosophy

published_or_final_version / Physics / Master / Master of Philosophy

Obesity increases the risk for the development of cardiovascular disease, type 2 diabetes and other co-morbid conditions. Type 2 diabetes also is often associated with excessive visceral abdominal fat. Weight loss in obese individuals decreases the risk for developing the co-morbid conditions. Individuals with type 2 diabetes often have a greater difficulty in controlling these complications compared to individuals without type 2 diabetes. The purpose of this study was to evaluate adherence to a medically-supervised low-energy diet (LED) weight loss program and changes in body composition and metabolic parameters after weight loss in women with and without type 2 diabetes. Subjects consisted of Caucasian women, between the ages of 40 to 65 years, with BMIs between 30 and 45 kg/m2. There was no significant difference in BMI between the groups at study initiation (38.1 kg/m2, diabetics (DM) and 36.0 kg/m2, non-diabetics (NDM), p=0.2314). All subjects participated in the HMR Program for 16 weeks. Twenty-nine subjects completed the weight loss phase (18 diabetics, 11 non-diabetics) and were evaluated for change in weight, body composition, and blood parameters. Data were analyzed by repeated-measures ANCOVA and students t-tests using SAS version 8.02. DM and NDM lost 11.7% and 16% of body weight, respectively (p=0.6474). Results indicate DM has more total lean tissue (p=0.004), more total body fat (p=0.04), more total abdominal tissue (p=0.001), more visceral adipose tissue (p=0.001) and lost less percent body fat (p=0.04) than NDM after 16 weeks of weight loss. After weight loss there was no significant difference in leptin, ghrelin or adiponectin levels. DM had greater insulin (p=0.05), HOMA-IR (pandlt;0.0001), glucose (pandlt;0.0001), HbA1c (pandlt;0.0001), resistin (p=0.04) and PAI-1 (p=0.02). There were no differences after weight loss in lipid levels, blood pressure, diet compliance or exercise. The data show that medically-supervised LEDs are safe and effective for treating obesity in individuals with type 2 diabetes. Cardiovascular risk factors improved in both NDM and DM subjects with weight loss. The findings also suggest that insulin and metabolically dysfunctional lean tissue may play a critical role in the complex axes affecting changes in body composition and inflammation in individuals with type 2 diabetes.

Baigiamajame magistro darbe nagrinėjamos grunto ir atliekinės pastato šilumos panaudojimo galimybės mažaenergiame pastate, Vilniaus mieste, Lietuvoje. Suskaičiuoti keturi pastato energijos balansų variantai, naudojant ”CASAnova” kompiuterinę skaičiavimo programą, su skirtingais atitvarų šilumos perdavimo koeficientais. Pastate taikomos dvi energijos taupymo priemonės. Pirmoji yra gruntinis šilumokaitis naudojamas šviežio oro pirminiam pašildymui mechaninio vėdinimo sistemoje, kurio skaičiavimai atliekami ”GAEA” programa. Antroji yra nuotekų šilumos atgavimo šilumokaitis, naudojamas į pastatą tiekiamo šalto vandens pirminiam pašildymui, atgaunant dalį šilumos iš duše susidariusių nuotekų. Pastatui reikiamas metinis šilumos ir vėsos energijos kiekis gaminamas šilumos siurbliu su vertikaliu gręžiniu grunte, kurio skaičiavimams naudojama ”EED” programa. Gręžinių gyliai yra suskaičiuoti kiekvienam pastato energijos balansų variantui. Atlikti ekonominiai skaičiavimai rodo gruntinio ir nuotekų šilumos atgavimo šilumokaičių įdiegimo pastate ekonominę naudą. Pateikti rezultatai rodo kiekvieno varianto energijos poreikius ir gręžinio grunte gylį priklausomai nuo pastato varianto atitvarų šiluminių savybių bei taikomų energijos taupymo sprendimų. Darbą sudaro 9 dalys: įvadas, 6 skyriai, išvados ir pasiūlymai, literatūros sąrašas. Darbo apimtis – 64 psl. teksto, 41 paveikslai, 14 lentelės, 31 bibliografinis šaltinis. / The final master thesis presents technical analysis of low-energy residential building in Vilnius, Lithuania. Building has low temperature floor heating, mechanical ventilation with heat recovery unit and hot water preparation with buffer tank systems. Using “CASAnova” software is calculated fourth energy balances of building according fourth different heat transfer coefficients of the walls. All heating and cooling energy demand of a building is generated from the ground. It is made by using a heat pump with single borehole. A calculation of borehole sizing is made with “EED” software. Two energy saving technologies are analysed for a building. The first idea is to reduce heat energy consumption of hot water preparation. There is calculated benefit of waste water heat recovery heat exchanger which function is to pre-heat hot water using waste water from the shower. Second idea is to reduce heat energy consumption for fresh air heating in air handling unit. There is calculated benefit of earth-to-air heat exchanger using “GAEA” software. Final result of all calculations shows influence of heat transfer coefficient and energy saving technologies to building annual energy balance and depth of borehole. Economic benefit of using energy saving technologies is calculated. Structure: introduction, 6 chapters, conclusions and suggestions, references. Thesis consists of 64 p. of text, 41 figures, 14 tables and 31 bibliographical entries.

Los grandes avances tecnológicos se han producido una serie de artefactos electrónicos que mejoran la calidad de vida de la personas. Estos artefactos pueden visualizarse en el hogar como los electrodomésticos, equipos de entretenimiento o dispositivos de seguridad. Actualmente, existe una tecnología llamada domótica que consiste en automatizar los artefactos eléctricos del hogar. Esta tecnología presenta varias soluciones en el mundo, donde cada una tiene distintas maneras de implementación y propósitos. Por eso, los precios de los productos generados por estas soluciones son considerablemente altos para el mercado peruano y latinoamericano. Asimismo, estas soluciones presentan una carencia de soporte para estos mercados. Por estas razones, este artículo propone la implementación de una solución de domótica que utilizando un modelo definido basado en las mejores prácticas del mercado actual se pueda generar una solución de bajo costo, de gran alcance y que sea económicamente accesible para el mercado peruano y latinoamericano. Para esto se estudiará los actuales métodos de comunicación para la creación de los dispositivos de domótica. Además, se evaluará las soluciones existentes de domótica, obteniendo el conocimiento de sus problemáticas, resultados y recomendaciones para poder tener una base con la cual sustentar las mejoras y ventajas de la propuesta a desarrollar.