As sensing technology develops, it plays an important role in context-aware systems. Using context information improves the user experience of ubiquitous computing. One use of sensed information is to detect a meeting in progress in an office or a conference room. In our system, sensors gather context information from an office environment and act as a presence user agent to update a presence server with context changes. These context changes can be utilized by context-aware services. The presence messaging uses the SIP for Instant Messaging and Presence Leveraging Extensions (SIMPLE) protocol and the presence information is described in eXtensible Makeup Language (XML) format. In this thesis we present a context-sensing component that recognizes meetings in a typical office environment. A context-aware system is able to use this occupancy information to infer that the room is empty, an individual is alone in the room, or a meeting is taking place in the meeting room. Context-aware services might utilize this environmental information to automatically forward a user's incoming calls to their voice mail server. This and other example applications were developed to show the usefulness of this context information. / Så som sensor tekniken utvecklas, spelar de en viktig roll i kontextmedvetna system. Genom att använda kontextuell information förbättras användarupplevelsen av 'ubiquitous computing'. Ett användningsområde för sensorinsamlad information är att upptäcka ett möte som pågår i ett kontor eller konferenslokal. I vårt system samlar sensorer information från en kontorsmiljö och uppdaterar en närvaroserver med kontextuella förändringar. Dessa förändringar kan sedan utnyttjas av kontextmedvetna tjänster. För att förmedla den närvarostatusen använder närvaroservern SIP och ’Presence Leveraging Extensions’ (SIMPLE) protokoll. Närvaro information levereras i 'eXtensible Makeup Language' (XML) format. I denna avhandling presenterar vi en kontextsensorkomponent som känner av möten i en typisk kontorsmiljö. Ett kontextmedvetet system kan använda denna komponent för att dra slutsatsen att lokalen är tom, en person är ensam i lokalen, eller ett möte äger rum i lokalen. Kontextmedvetna tjänster kan utnyttja denna information för att automatiskt vidarebefordra en användares inkommande samtal till deras röstbrevlåda. Detta och andra exempel, har utvecklats för att visa nyttan av denna kontextuella information.

Residential solar Photovoltaic (PV) installations are increasing at a very high pace in the United States. In 2017 there are approximately one million residential solar PV installations in the US. A significant share of these installations are downstream of distribution transformers and thus connected to the secondary. To precisely analyze voltage variations induced by PV systems into distribution systems, accurate models of load and PV systems connected to the secondary side of distribution transformers are required. In the work here we consider two secondary circuit modeling approaches, simple secondary and detailed secondary models. In simple secondary models all loads and all PV generators below a distribution transformer are modeled as an aggregate load and an aggregate PV generator. In the detailed secondary models all loads and PV systems below the distribution transformers are modeled individually and secondary conductors and service drops are also modeled. Using a cloud motion simulator, it is observed that employing the simple secondary models can lead to inaccurate and conservative results. Moreover, the locations with the greatest voltage changes are different in the two modeling approaches. This paper highlights the importance of utilizing detailed secondary models over simple secondary models in analyzing PV generation. / Master of Science / Power system planners and operators rely on computer-based modeling and analysis of the electric grid to ensure that electricity is delivered to consumers in a reliable manner. The current modeling is done either to simulate the high voltage transmission networks, or the primary distribution networks. Till now these modeling approaches have worked well as the electricity flow in the electric grid is largely unidirectional, i.e. power flows from the transmission network to the distribution network. Neglecting the secondary distribution network topology in such a structure of the electric grid does not introduce significant calculation errors. However, the rapid growth of residential solar PV based distributed generation over the last few years, which is expected to continue into the foreseeable future, has motivated the need to rethink this modeling and analysis paradigm. As the penetration levels of distributed generation increase, there will be bi-directional flow of electricity between the transmission and distribution networks. Accurate analysis of such a decentralized electric grid cannot be performed if secondary distribution network topology is neglected in the models. So, to precisely analyze voltage variations induced by PV systems into distribution systems, accurate models of load and PV systems connected to the secondary side of distribution transformers are required. This thesis highlights the importance of using detailed models of secondary distribution.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

The American Heart Association Life's Simple 7 (LS7), a metric that classifies cardiovascular health using modifiable risk factors, has been reported to be associated with cognitive function. However, the assessment of cognitive function in prior studies has been limited to relatively crude global measures. We hypothesized that greater LS7 scores at baseline are associated with less cognitive decline and lower incidence of dementia and Alzheimer's. Using data from the core Health and Retirement Study survey (2012-2018), 2013 Health Care and Nutrition Questionnaire and enhanced face-to-face interviews we will evaluate cognitive scores in relation to LS7. The participants included in this analysis (n = 2,753) are greater than 50 years of age without dementia. A global cognitive score was calculated using the combination scores on multiple cognitive tests that include measurements of semantic memory, quantitative reasoning, episodic memory, and executive functioning. Changes in cognitive scores are evaluated based on marginal effects after adjustments for confounding variables. Baseline LS7 scores (0-14) were calculated using information on smoking habits, body mass index, habitual diet, blood pressure, non, physical activity, and hemoglobin a1c. Results were analyzed using linear mixed models fit with random intercepts and the use of Huber-White variance estimates to analyze the results. Knots were introduced to explain non-linear change in respondents. Global cognitive scores in all respondents decreased more between baseline to year two and year two to year four than year four to year six (ΔB-2: -2.796, Δ2-4: -3.362 v. Δ4-6: -1.191). A one unit increase in LS7 score presented a protective effect and slowed the rate of decline by 0.11 unit in global cognitive scores between baseline and year two. The protective effect was lower between year two and four (0.07 units) and non-significant between year four and six. Black respondents did not respond similarly in models than white respondents. A one unit increase in LS7 score increased the rate of decline from baseline to year two and year two to year 4 in black respondents (p<0.001, p<0.05). LS7 scores had no significant interaction with global cognitive scores between year 2 and 6. Serial 7 scores did not significantly change over time in any of the racial categories. A unit increase in LS7 scores showed a marginal protective effect on memory scores from year two to four in all respondents (r=0.03, p<0.001). In white respondents, higher LS7 scores had a protective effect on memory scores (r=0.01, p<0.05). The probability of developing dementia or Alzheimer's over the study period was the highest for males (P = 3.6%) than females (P = 3.3%) and lowest for white, females (P=13%) and highest for black, males (P=15%). Having higher LS7 scores at baseline is associated lower cognitive decline over a 6-year period in white, older adults. LS7 scores at baseline delayed word recall/memory scores over time but not serial 7/executive functioning scores. LS7 scores at baseline are not associated with lower incidence of cognitive impairment and dementia. Findings suggest better habits formed earlier in life have a better protective effect than late-life habits / Master of Science / The United States is dealing with a rapidly aging population. By the year 2035, there is expected to be more adults over the age of 65 than children. As the number of older adults increases as will the number of new and existing cases of Alzheimer's and other dementias. The burden of older adults with Alzheimer's and dementia strains the U.S. healthcare system therefore new research is emerging on interventions used to slow the onset of this life-altering disease before critical and expensive care is required. One method that has been effective is modifying lifestyle behaviors. In 2010 the American Heart Association classified the Life's Simple 7 (LS7) metrics which involved both behavioral and biological measures for cardiovascular risk assessment in Americans. The LS7 metrics include smoking behaviors, physical activity, diet, body mass index, blood pressure, cholesterol, and fasting blood glucose. The American Heart Association's LS7 metric adherence during early and mid-life has been shown to decrease risk for Alzheimer's and dementia, however, research of adherence in late-life is limited. Preventing late-life onset of dementia is vital to older adults therefore this study aims to observe late-life adherence LS7 and change in cognitive functioning over a 6-year period (2012-2018). Participants included in this study are from the Health and Retirement Study (HRS) that are 50 years and older without diagnoses of dementia or Alzheimer's at the time of baseline measurement in 2012. Late-life adherence to Life's Simple 7 metrics are associated with slower rates of cognitive decline in white respondents. The Life's Simple 7 metric is not significantly associated lower cases of dementia and is associated slower rates of decline in memory but not executive functioning. This study aimed to expand evidence for racial differences on global cognitive changes and domain-specific cognitive measurements and the effect Life's Simple Seven scores have on that relationship.

Loblolly pine is an important managed tree species within the southeastern United States, and better understanding spatial patterns in its productivity has potential to contribute to both modeling and management of the species. Using recently-created pine management maps specific to Virginia and empirical relationships predicting pine LAI from the Landsat satellite, we conducted a statewide analysis of temporal patterns in stand-level southern pine leaf area index (LAI) following clear-cut and planting. Here, using 28 years of Landsat time-series data for 13,140 stands that were clear-cut between 2014-2017, we examined 1) when LAI peaked over the rotation, and 2) how LAI in each stand compared to a recommended fertilization threshold of 3.5 LAI. We found that, on average, winter LAI reached a maximum of 2.02., which can be approximately doubled to give a summer LAI of 4.04, and within stand peak occurred between years 13 and 15. We also found that around 45.8% of stands achieved an LAI value higher than 3.5: a fertilization threshold recommended for managed stands in Virginia. The dataset produced by our analysis will bolster information required for modeling loblolly pines as a plant functional type in regional land simulations, and the finding that most stands are below the recommended LAI fertilization threshold will fuel further management-motivated research. / Master of Science / Management of pines in the southeastern U.S. contributes to the region's economy and carbon sequestration potential. In this study, we used Virginia forest harvest maps to identify individual patches (stands) of pine forest which had each gone through a full harvest life cycle (rotation). With unique managed pine stands identified, we used satellite imagery to estimate growth of canopy leaf area over time within each stand, using a metric called leaf area index (LAI). We identified 13,140 separate stands, each with up to 28 years of available data. We took the first full-state census of areas of managed pines in Virginia, and their leaf area development. We acquired one LAI measurement from February of each year, for each stand in Virginia. Using February LAI for each of our stands, we found that an average stand in VA has a maximum winter LAI of 2.02 (meaning an approximate maximum summer LAI of 4.04), and that stands generally reached their peak LAI after around 14 years of growth. It is recommended, in VA, that a landowner fertilize their stand in the middle of a harvest rotation if summer peak LAI is under 3.5, at stand closure. We found that at ten years of stand age, 45.8% of stands were estimated to reach above this threshold. Since this study's dataset is the most comprehensive LAI dataset for managed pines in VA, it may be used to improve management outcomes as well as understand pine productivity for land surface modeling purposes.

Ungdomar läser allt mindre i Sverige och senaste PISA- undersökningen visar sjunkande resultat vad gäller bland annat läsförmåga hos svenska ungdomar. En stor del av forskningen fokuserar på läsutveckling med yngre elever, därför är studiens syfte att undersöka speciallärares/specialpedagogers beskrivningar av arbetet för att främja elevers läsutveckling på mellan- och högstadiet. Frågeställningarna är: Hur beskriver speciallärare/specialpedagoger att de arbetar förebyggande med elevers läsutveckling? Hur beskriver speciallärare/specialpedagoger att de arbetar åtgärdande med elevers läsutveckling? Hur beskriver speciallärare/ specialpedagoger det systematiska arbetet kring elevers läsutveckling? Studiens teoretiska utgångspunkter är sociokulturellt perspektiv, Simple View of Reading och Response to Intervention. Det är en kvalitativ studie med semistrukturerade intervjuer där tio speciallärare beskriver sitt arbete för att främja läsutveckling. Materialet delades in i sex olika teman; att hitta elevens nivå, skolans samarbete och organisation kring läsutveckling, assisterande teknik, elevers läsmotivation, metoder och material samt, speciallärarstöd i klass, liten grupp eller med enskilda elever. Resultatet visade att speciallärarnas arbete varierar stort beroende på lokala förutsättningar och att speciallärarna/specialpedagogerna arbetar med läsningens olika delar på olika sätt, men att metoder och material som används varierar oerhört mycket. Speciallärarna/specialpedagogerna i studien är måna om att hitta elevens närmaste utvecklingszon för att sätta in rätt stöd vid rätt tid, vilket stämmer väl med Response to Intervention. Resultatet diskuteras.

Constructible numbers are the numbers that can be constructed by using compass and straightedge in a finite sequence. They can be produced from natural numbers using only addition, subtraction, multiplication, division, and square root operations. These operations can be repeated, which creates more complicated expressions for a mathematical object. Calculation by computers only gives an approximation of the exact value, which could lead to a loss of accuracy. An alternative to approximation is exact arithmetic, which is the computation to find an exact value without rounding errors. In this thesis, we have presented a method of computing with the exact value of constructible numbers, specifically the rational numbers and its field extension as well as repeated field extension, through the basic operations. However, we only limit our implementation to the quadratic polynomial and the operations between two numbers of the same extension field. Future work on polynomials with higher degrees and algorithms to include operations with numbers from different extension fields and expression of number as an element of a new extension field remains to be done.

Syftet med studien är att undersöka F-3 lärares uppfattningar om Skolverkets Nationella bedömningsstöd i Läsa och LegiLexis kartläggningsmaterial för läsutveckling. Studiens teoretiska utgångspunkter är läsmodellen The Simple View of Reading och lässtrategierna ljudningsstrategin och helordsläsning samt formativ och summativ bedömning. Vi har använt oss av intervjuer som datainsamlingsmetod och för att bearbeta samt analysera materialet använde vi oss av en tematisk analys. Resultatet presenteras utifrån respektive bedömning med samma teman och subteman som kopplas till studiens forskningsfrågor. Resultatet visar hur lärarna genomför bedömningarna, hur bedömningarna används i den fortsatta undervisningen samt vilka möjligheter och hinder som finns med respektive bedömning. En slutsats vi kan dra är att bedömningarna kräver varierade förutsättningar gällande tid, personal och verktyg. Det framkom dock att LegiLexis bedömning är mer tidseffektivt och kräver mindre personal vid själva genomförandet.

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No / PURPOSE. This study examined the influence of stimulus chromaticity on simple reaction times (RTs) to determine the stage of chromatic processing that is most influential in their generation. METHODS. Simple RTs were measured in response to the cosinusoidally ramped onset of small, equiluminant, colored Gaussian spots. The chromaticity of these stimuli was varied, to modulate along a series of vectors in color space that included red-green (L-M) and blue-yellow (S-[L+M]) opponent axes. RESULTS. RTs are highly sensitive to small departures from subjective equiluminance. They are also dependent on stimulus chromaticity. The longest RTs are generated in response to equiluminant stimuli that isolate S-cone activity, whereas the shortest are generated by stimuli that modulate the L-M opponent axis. However, temporal processing differences are highly dependent on how the chromatic stimuli are scaled in relation to one another. The differences are reduced when scaling is based on detection threshold. The relationship between chromatic contrast and RT can be described by the modified Piéron equation RT = RT0 + k · C-1. CONCLUSIONS. Simple RTs generated in this study conform to the idea that they are largely determined by cone-opponency mechanisms. The use of cone contrast as a metric for scaling chromatic stimuli exaggerates differences between the temporal responsiveness of L-M and S-(L+M) opponency mechanisms.