11 |
Communication protocols for mid-range mobile IoT devices : And their applicability to a publicly shared bikes platformLundh, Oskar January 2017 (has links)
Internet of Things, or the infrastructure of the information age society, is an expanding area of research. It is the idea that physical things that we have today, can be turned into devices by being connected to a network. The purpose of these devices is through more sensors and actuators, allow smarter and more robust infrastructure to be built, as well as improving consumer devices interoperability. This thesis will investigate the current state of the art application layer communication protocols that have been developed with resource constrained mobile devices in mind. It will look specifically at high latency mid-range wireless cellular communication by investigating how the protocols affect energy consumption for an embedded Internet of Things device. This is done with the constraint that these findings needs to be applicable to the fifth generation of cellular networks, as well as extensions to current generation standards. The application layer communication protocols Constrained Applications Protocol(CoAP), Message Queue Telemetry Transport(MQTT) and Hypertext Transfer Protocol(HTTP) used on multiple modem modules, are investigated in a quantitative approach in deductive survey experiments, testing a variety of what is concluded to be typical sensor and actuator scenarios. The goal with the survey, is to ultimately select the protocol that shows to be the most suitable for a project to build a prototype platform for embedded mobile devices in the shape of publicly shared bikes in a city. This prototype is described and its architecture and design decisions are presented and argued for. The survey discovers that CoAP is the most suitable protocol for the purpose of the thesis, and proceeds to show how it is applied to the described platform.
|
12 |
Modelling of additive manufacturing deposition for aerospace applications : A cross sectional bead geometry model validated for directed energy deposition using titanium blown powderWulff, Christopher January 2024 (has links)
In an effort to make the aerospace industry more sustainable, GKN Aerospace is heavily investing both time and money into additive manufacturing technologies. A challenging aspect with additive manufacturing is finding a set of process parameters that produces high quality parts and components to a standard that the aerospace industry demands. To aid the process development, turning to simulations is a great alternative and with the prospect of adding to the tools available, the work of this thesis has been focused on developing a mathematical model of the cross sectional deposition geometry. Through a literature study, an initial approach to developing such a model, as well as gaps in knowledge was established. Validation data was gathered by laser scanning additively manufactured builds. A model based on a fourth degree polynomial was developed. The fourth degree polynomial model was validated with the laser scan data using the mean squared error value and coefficient of determination as a quantifiable method of determining the goodness of fit. It was found to be an improvement over the common parabolic model found in the literature based on a second degree polynomial. The improved model manages to capture a wide variety of contact angles and the overlap region better follows the smooth transition between beads.
|
13 |
Thermo-mechanical Analysis of Laser Hot-wire Directed Energy Deposition (LHW-DED) Additive Manufacturing ProcessKalel, Mukesh 03 May 2023 (has links)
No description available.
|
14 |
En utvärdering av Non-Invasive Break-Up Time och Tear Break-Up Time hos heltidsstuderande vid Linnéuniversitetet / An evaluation of Non-Invasive Break-Up Time and Tear Break-Up Time in full-time students at Linnaeus UniversitySvedin, Lina, Norrby, Rebecka January 2024 (has links)
Syfte: Syftet med studien var att utvärdera NIBUT (Non-Invasive Break-Up Time) och TBUT (Tear Break-Up Time) hos heltidsstuderande vid Linnéuniversitetet samt bidra till en ökad förståelse av ögonhälsan hos denna grupp. Metod: Tårfilmens stabilitet kontrollerades med NIBUT och TBUT, tiden mättes direkt efter en blinkning till första uppsprickningen av tårfilmens yta eller ny blinkning. NIBUT utfördes icke invasivt i Sirius och TBUT mättes i biomikroskop med fluorescein. Deltagarna fick inledningsvis svara på en enkät som gjorde det möjligt att analysera insamlad data utifrån ålder, kön, termin, skärmtid och poäng på DEQ-5 (5-Item Dry Eye Questionnaire). Svaren från DEQ-5 möjliggjorde att resultaten från NIBUT och TBUT mätningarna kunde jämföras mot upplevda symtom på torra ögon. Resultat: Studien inkluderade 36 studenter i åldersspannet 18–39 år (medianålder 23 år, IQR 5,25 år). NIBUT och TBUT visade en positiv signifikant korrelation (p <0,001). En kortare TBUT korrelerade negativt med en högre totalpoäng på DEQ-5 (p = 0,004) samt antalet terminer som studerats (p = 0,025). NIBUT visade inte några liknande samband. Referensvärdet för torra ögon diagnostisering med hjälp av NIBUT och TBUT är en tid <10 sekunder. Över hälften av deltagarna i studien, NIBUT 58% och TBUT 53%, hade en nedsatt break-up time <10 sekunder. Vilket kan vara en indikation för torra ögon problematik. Slutsats: Denna studie visar att det finns ett signifikant samband mellan NIBUT och TBUT mätningarna. Kortare TBUT har visat en signifikant korrelation med högre totalpoäng på DEQ-5, likaså har signifikanta samband mellan TBUT och fler lästa terminer konstaterats. Trots korrelationen mellan NIBUT och TBUT påverkades resultaten av skillnader mellan de två mätmetoderna. / Purpose: The purpose of the studies was to evaluate NIBUT (Non-Invasive Break-Up Time) and TBUT (Tear Break-Up Time) in full-time students at Linnaeus University and to contribute to an increased understanding of the eye health of this group. Method: The stability of the tear film was checked with NIBUT and TBUT, the time was measured directly after a blink to the first break-up of the tear film surface or a new blink. NIBUT was performed non-invasively in Sirius and TBUT was measured in a biomicroscope with fluorescein. The participants initially had to answer a questionnaire that made it possible to analyze collected data based on age, sex, number of semesters studied, screen time and score on the DEQ-5 (5-Item Dry Eye Questionnaire). The responses from the DEQ-5 allowed the results from the NIBUT and TBUT measurements to be compared against perceived symptoms of dry eye. Results: The study included 36 students in the age range 18–39 years (median age 23 years, IQR 5.25 years). NIBUT and TBUT showed a positive significant correlation (p <0.001). A shorter TBUT correlated negatively with a higher DEQ-5 total score (p = 0.004) as well as the number of semesters studied (p = 0.025). NIBUT did not show any similar correlations. The reference value for dry eye diagnosis using NIBUT and TBUT is a time <10 seconds. Over half of the participants in the study, NIBUT 58% and TBUT 53%, had a reduced break-up time <10 seconds. Which can be an indication of dry eye problems. Conclusion: This study shows that there is a significant connection between the NIBUT and TBUT measurements. Shorter TBUT has shown a significant correlation with higher total scores on the DEQ-5, likewise significant connections between TBUT and more semesters read have been established. Despite the correlation between NIBUT and TBUT, the results were influenced by differences between the two measurement methods.
|
15 |
Towards Control of Dutch Elm Disease: dsRNAs and the Regulation of Gene Expression in Ophiostoma novo-ulmi / dsRNAs and the Regulation of Gene Expression in Ophiostoma novo-ulmiCarneiro, Joyce Silva 01 August 2013 (has links)
Ophiostoma novo-ulmi is the causal agent of Dutch elm disease (DED) which has had a severe impact on the urban landscape in Canada. This research program focused on developing molecular genetic strategies to control this pathogenic fungus.
The first strategy involved the development of RNA interference (RNAi) for the down-regulation of genes involved in pathogenicity. An efficient RNAi cassette was developed to suppress the expression of the endopolygalacturonase (epg1) locus which encodes a cell-wall degrading enzyme. This epg1-RNAi cassette significantly reduced the amount of polygalacturonase activity in the fungus and resulted in almost complete degradation of epg1 mRNA. The need for a native promoter to selectively down-regulate specific gene loci was addressed by developing a carbon-catabolite regulated promoter (alcA) to drive the expression of the epg1-RNAi cassette. The expression of an alcA-driven epg1-RNAi cassette resulted in the down-regulation of epg expression under glucose starvation but normal levels of expression in high glucose. The expression could therefore be controlled by culture conditions.
The second strategy explored the potential of using dsRNA viruses to vector disruptive RNAi cassettes. An isolate of O. novo-ulmi strain 93-1224 collected in the city of Winnipeg, was infected by two dsRNA mitoviruses which upon sequence characterization were named OnuMV1c and OnuMV7.
To assess the transmissibility of this dsRNA virus the infected isolate 93-1224 was paired with three naive isolates of the related fungi O. ulmi and O. himal-ulmi. Through the use of nuclear and mitochondrial markers it was determined that the virus OnuMV1c may not rely on mitochondrial fusion for transmission but may have a cytoplasmic transmission route.
This investigation of gene expression and manipulation has provided tools to help understand gene regulation in O. novo-ulmi. It has also added to our knowledge of mitoviruses, their transmission and potential use as a biological control. By enhancing our understanding of transmissible hypovirulence this work contributes to efforts to develop a new approach to target DED as well as a potential model for the control of other fungal diseases. / Graduate / 0307 / 0306 / 0369 / jscarneiro@hotmail.com
|
16 |
The Kamchay Hydropower Project -Hydropower development in Cambodia and eastern AsiaMalmquist, Peter, Sigfridsson, Mats January 2003 (has links)
The objective in this case study is to highlight typical problems of a planned hydropower dam project in Bokor National Park, Cambodia. The focal point in the line of questioning is the usage of public participation in larger exploration plans in a development country and to give a comprehensive survey of some of the participant involved. The study also discusses how the WCD report is used by non-govemental organisation to validate their claims. To be able to understand how the Cambodian society works, the study also includes a short briefing of recent Cambodian history. The study shows that the local people are more or less neglected in the preliminary investigations. Even if information meetings are held open, they are conducted in such a way that it is hard for common people to participate. The meetings are held in English and not in the domestic language Khmer. Critical groups are not formally invited but welcome to attend, most of their statements are withdrawn from the official protocols. The study also reveals that the leading entrepreneurs more or less neglects the environmental hazards in the construction by focus their information and calculations on the positive effects of the project. The study has been made as a field study, on location in Cambodia.
|
17 |
En jämförande studie av två metoder för analys av tårfilmen : En pilotstudieEdström, Ola, Gerebo, Linnéa January 2024 (has links)
Syfte: Syftet med studien var att jämföra två metoder vid undersökning av tårfilmsanalys; tårflödesbeteende-metoden och fluorescein break-up mönster och om deras mätresultat överensstämmer med varandra. Detta för att diskutera om någon av metoderna kunde vara ett bättre alternativ att adaptera ute i praktiken för vårdgivare inom ögonvården. Metod: Initialt fick deltagarna besvara en OSDI-enkät (ocular surface disease index), därefter gjordes resterande mätningar i biomikroskopet. I biomikroskopet utfördes initialt dem icke-invasiva mätningarna som tillhörde tårflödesbeteende-metoden (mätning av TMH (tårmeniskhöjd), debrishastighet efter blinkning och mätning av lipidlagrets interferensmönster) även NiBUT (non-invasive tear break-up time) utfördes. Efter dem icke-invasiva mätningarna tillsattes fluorescein i inferiora temporala fornix och dem invasiva testerna; TBUT (tear break-up time) och FBUP (fluorescein break-up mönster) utfördes tre gånger. Alla mätningar dokumenterades med video. Tre oberoende bedömningar utfördes. Studien undersökte om resultatet av tårflödesbeteendet och FBUP hade ett samband och vilken utav metoderna som fick en högre intravaliditet utefter dem bedömningar som utfördes. Resultat: Totalt deltog 26 deltagare varav 4 exkluderades. Deltagarna var mellan 19–57 år gamla med en genomsnittsålder på 35 år och en standardavvikelse på ±12,3 år. Samtliga presenterade med en OSDI ≥13, alternativt hade en visuellt frekvent blinkfrekvens. Det återfanns ett samband mellan tårflödesbeteende-metoden och FBUP i studien, dock ingen av klinisk signifikans ((bedömare 1, Cramer’s V= 0,46 p=0,06) (bedömare 2, Cramer’s V=0,33 p=0,32) (bedömare 3, Cramer’s V=0,33 p=0,34)). Tårflödesbeteende-metoden (Fleiss kappa =0,29, p=0,40) och FBUP (Fleiss kappa =0,25, p=0,40) uppvisade båda på en mindre god intra-validitet Slutsats: Det finns ett samband mellan tårflödesbeteende-metoden och FBUP men ingen statistisk signifikans. Intravaliditeten är marginellt högre vid tårflödesbeteende-metoden än vid FBUP i studien. / Aim: The aim of this study was to compare two methods used during tear-film analysis; tear-flow behaviour, and fluorescein break-up pattern and if their measured results are in an agreement. This in order to discuss which one of the methods would be more suitable to apply in clinical practice for healthcare workers in the field of optometry. Method: Initially the participants filled out an OSDI questionnaire (ocular surface disease index), thereafter measurements were done in the biomicroscope. Initially the non-invasive measurements such as the tear-flow behaviour method (measurements of TMH (tear meniscus height), speed of debris movement across the tear film after blinking and measurements of the lipid layer interference) and NiBUT (non-invasive break-up time) were measured. Afterwards fluorescein was applied in the inferior temporal fornix and the invasive measurements; TBUT (tear break-up time) and FBUP (fluorescein break-up pattern) were measured three times. All measurements done in the biomicroscope were documented with video and three independent assessments were done. This study looked at the results from the tear-flow behaviour and FBUP and if they agreed with one another. It also looked into which one of the methods presented a higher intra-validity in regard to the assessments made. Results: The study had a total of 26 participants, of which 4 were excluded. The participants were between the ages of 19-57 years old with an average age of 35 years with a standard deviation of ±12,3 years. The participants presented with an OSDI of ≥13, with exceptions made if a participant visually had a high blink frequency. A correspondence between the tear-flow behaviour method and FBUP could be observed, however none of statistical significance ((assessor 1, Cramer’s V= 0,46 p=0,06) (assessor 2, Cramer’s V=0,33 p=0,32) (assessor 3, Cramer’s V=0,33 p=0,34)). The intra-validity of the tear-flow behaviour method (Fleiss kappa =0,29, p=0,40) and FBUP (Fleiss kappa =0,25, p=0,40) were both categorized as weak intra-validity. Conclusion: There is a correspondence between the tear-flow method and FBUP, without statistical significance. The intra-validity was marginally higher within the tear-flow method compared to FBUP in the study.
|
Page generated in 0.0426 seconds