The Unified Extensible Firmware Interface (UEFI) is the industry-standard Basic Input/Output System (BIOS) firmware specification used by modern desktop, portable, and server computers, and is increasingly being ported to today's new mobile form factors as well. UEFI is firmware responsible for bootstrapping the hardware, turning control over to an operating system loader, and then providing runtime services to the operating system. ANTLR (ANother Tool for Language Recognition) is a lexer-parser generator for reading, processing, executing, and translating structured text and binary files. It supersedes older technologies such as lex/yacc or flex/bison and is widely used to build languages and programming tools. ANTLR accepts a provided grammar and generates a parser that can build and walk parse trees. This report studies UEFI BIOS and compiler theory and demonstrates ways compiler theory can be leveraged to solve problems in the UEFI BIOS domain. Specifically, this report uses ANTLR to implement two language applications aimed at furthering the development of UEFI BIOS implementations. They are: 1. A software complexity analysis application for UEFI created that leverages ANTLR's standard general-purpose C language grammar. The complexity analysis application uses general-purpose and domain-specific measures to give a complexity score to UEFI BIOS modules. 2. An ANTLR grammar created for the VFR domain-specific language, and a sample application which puts the grammar to use. VFR is a language describing visual elements on a display; the sample application creates an HTML preview of VFR code without requiring a developer to build and flash a BIOS image on a target machine to see its graphical layout. / text

The visiting friends and relatives segment has not been given much study, because the segment has been perceived as small and with no positive economic impact on destinations. This is because of the belief that VFR travelers sleep and eat at their friends’ and relatives’ houses. Lately, the definition of VFR travelers has been changing due to more studies in the area. The results of these studies have shown that the size of the segment has been underestimated, as has the economic impact the segment has on a destination. This thesis is a complement to Bischoff and Koenig-Lewis study ”VFR Tourism: the Importance of University Students as Hosts”. The purpose of this thesis is to examine how students at Umeå university affect the tourism industry in Umeå. The thesis aims to study the frequency of visits made by the students’ friends and relatives, seasonal distribution of the visits, visitor motives, and economic factors linked to these visits. The study is based on a questionnaire survey with closed-ended questions. The study was conducted through descriptive statistical analysis of the questionnaire. Results of the study indicates that the main reason for friends and relatives to visit students in Umeå is to be with the student in question. Most of the VFR travelers stay at their host’s place, with only a few percent using commercial accommodation. Instead VFR travelers have more economic impact on restaurants, shopping and nightlife.

Visiting friends and relatives is one of the oldest reasons for travelling. This form of travel is a way for friends and relatives to stay connected even if they live in different cities orcountries. Visiting Friends and Relatives, also called VFR tourism, is still important today. Even though some studies have been made in Australia, Germany, and Great Britain there is still a lack of research in other parts of the world. This means that this form of research is stillnecessary, especially in the northern countries. This study will contribute with a Swedish perspective by examining weather students at Umeå University received visits from friends and relatives during their time of study.  The aim of this paper is to analyze how the presents of students affect the numbers of VFR tourists. A survey containing questions about visiting friends and relatives, activities and the students and their visitor’s behaviour during these visits was used to investigate this correlation.  The result showed that the relationship between VFR tourists and students can be linked to migration. When students move, they function as a link between their old and new homeswhich is shown when friends and relatives choose to travel to visit them. The result also shows that students behave a bit differently during these visits and experience things that would not have experienced otherwise.

This research examined human-machine performance in a General Aviation (GA) environment under dynamic conditions using a combination of field study and laboratory experimentation. Using this combination of methods, the functional system of pilots performing a landing approach (both instrument and visual) with a Cessna 172 to the Roanoke Regional Airport (ROA) was described and analyzed. In the field study, data collection was guided by an integrative method based on macroergonomics (ME) and distributed cognition (DC), allowing the cognitive aspects of a sociotechnical system to be treated as equally important as the organizational components. Also of interest was how pilot performance was affected by the introduction of nighttime and deteriorating weather conditions to this GA environment. Few statistically significant differences were found between pilots who flew by visual flight rules (VFR) and those who flew by instrument flight rules (IFR) or within each of these pilot groups in terms of objective flight performance. However, there were several significant differences between VFR and IFR pilots and within each pilot group in terms of workload and especially situation awareness across conditions; situation awareness for VFR pilots was found to be significantly reduced compared to situation awareness for IFR pilots in nighttime and deteriorating weather conditions (p < 0.05). In addition to these statistical findings and the methodological contribution of a joint systems/cognitive method, contributions of this dissertation include a greater understanding of the GA pilot/cockpit system and a systems-oriented cognitive model of this aviation environment as described by the ME/DC method for both VFR and IFR pilots. Further, procedural comparisons were performed between the flight simulator and the actual Cessna 172 used in the field study to increase our understanding of how to improve the validity associated with using simulators in research. Findings from both the laboratory and field studies in this research support new designs and technologies envisioned for future aviation systems that would assist the pilot during a landing approach such as weather information systems, head-up displays, synthetic vision, three-dimensional auditory displays, increased automation, and communications filters. Potential future applications of this research are also explored. / Ph. D.

Pseudomonas aeruginosa is a gram-negative pathogen that causes opportunistic infections in immunocompromised individuals. Whereas clinical isolates from acute infections are characterized by host cell cytotoxicity and motility, isolates from chronic infections are characterized by biofilm formation and persistence. The type III secretion system (T3SS) causes cytotoxicity by injecting effectors into host cells. T3SS gene expression is activated by ExsA, an AraC family transcriptional regulator. Transcription of exsA is controlled by two promoters, PexsC and PexsA, which are regulated by ExsA and the cAMP-Vfr system, respectively. Additional global regulatory systems also influence T3SS including the second messenger signaling molecule c-di-GMP and the RsmAYZ regulatory system. c-di-GMP signaling increases biofilm production and decreases acute virulence factor expression. A previous study found that c-di-GMP alters cAMP levels and affect cAMP-Vfr signaling. Other studies found that c-di-GMP signaling alters expression of the small non-coding regulatory RNAs, rsmY and rsmZ. The RsmAYZ post-transcriptional regulatory system regulates ExsA translation. We hypothesize that c-di-GMP regulates T3SS expression by altering exsA transcription through the cAMP-Vfr dependent PexsA promoter. Overexpression of YfiN, a c-di-GMP synthase, decreases T3SS reporter activity in PA103 and requires a functional GGDEF active site for full inhibition. Inhibition by YfiN does not require rsmYZ. YfiN expression decreases cAMP-Vfr signaling and coordinately inhibits PexsA-lacZ reporter activity. Consistent with the proposed model, YfiN expression in a vfr mutant does not further decrease T3SS reporter activity. These data indicate that the YfiN alters T3SS expression through transcriptional control of the cAMP-Vfr dependent PexsA promoter.

The United States (US) witnessed remarkable growth in annual long distance travel over the past few decades. Over half of the long distance travel in the US is made for pleasure, including visiting friends and relatives (VFR) and leisure activities. This trend could continue with increased use of information and communication technologies for socialization, and enhanced mobility being achieved using fuel-efficient (electric/hybrid) and technology enhanced vehicles. Despite these developments, and recent interest to implement alternate mass transit options to serve this market, not much exists on the measurement, analysis and modeling of long distance pleasure travel in the U.S. Statewide and national models are used to estimate long distance travel, but these are predominantly trip-based models, making it difficult to understand long distance trips as collection of household-level travel behavior. This form of travel behavior has been studied a lot in tourism, but in a piecemeal manner, such as to (from) a specific destination. Further, most of these studies are confined to analyzing leisure market, with VFR market gaining recognition only recently. In essence, annual household long distance pleasure travel behavior needs to be studied in a comprehensive manner rather than as isolated trips. This is because, most of these household travel decisions are undertaken considering their annual time and monetary budget, and their perceived cost to travel to one (or more) destination for given pleasure purpose on one (or more) occasion using a given mode of travel. Thus, the main objective of this dissertation is to develop a comprehensive behavioral model framework to analyze the above-discussed annual household long distance pleasure travel choices. To start the above effort, it is first required to collect detailed annual household travel data, last collected over two decades ago (e.g.: ATS, 1995). No such recent effort has been pursued due to the significant labor and economic resource required to undertake it. There exist recent surveys (NHTS, 2001), but collected over a shorter (four week) period, and require significant processing even to arrive at aggregate annual travel estimates. Second, besides surveys, there is a need for additional data to estimate households’ annual pleasure travel budget, and their cost to travel and stay at each of their potential destination choices, which are not readily available. Thus, as the first goal, this dissertation analyzes long distance travel reported across historical surveys (NPTS; ATS; NHTS), to understand the differences in their definition, enumeration of purpose and collection methods. The intent here is twofold, first to conceive a method to estimate annual travel from surveys with shorter collection period. Further, the second intent is to gather travel patterns from these historical datasets such that it informs the second goal of this dissertation, i.e. development of a behavioral framework to analyze annual household pleasure travel. To this effect, this research also analyzes pleasure expenditures using Consumer Expenditure Survey (CEX, BLS) data. Interestingly, the analysis reveals CEX pleasure travel expenditure pattern to be similar to the travel pattern reported for the same market segments in travel survey (ATS). Importantly, the above analysis informs the development of behavioral models, pursued as two distinct tasks to achieve the second goal. As the first task, a novel econometric model and forecasting procedure is developed to analyze a household’s annual long distance leisure travel decisions. Specifically, a households’ time spent across one (or more) destination and travel mode to such destination for leisure is modeled subject to time and money budget constraints. In this methodological framework, the destination choice is modeled as a continuous variable (time at destination) using Multiple-Discrete Continuous Extreme Value model (MDCEV). While, travel mode choice to these destination(s) are modeled as a discrete choice, through a nested Multinomial Logit Model (MNL), with price variation introduced across the above choice of destination(s) and travel modes (air/ground). This required estimating annual monetary budgets, travel cost and per night lodging cost for each sample household, with each of them having 210 potential destinations and 2 travel mode choices respectively. The second task, involved the development of a broader national model system to analyze households’ annual pleasure travel decisions such as: choice (duration) at destination(s), travel purpose (VFR or leisure), mode (airplane or auto) choice and trip frequencies to these destination(s) using the same dataset. It was modeled in two stages, with the first stage estimating households’ annual pleasure time budget using a stochastic frontier model. This budget was then used as constraint to analyze households’ annual choice of destination and purpose using a nested MDCEV-MNL model in the second stage. A log sum variable from a nested joint multinomial logit model of trip frequency and mode choice for each purpose (VFR or leisure) is also introduced as input at this stage. This model was then validated using a prediction procedure, and further applied to test a policy scenario (increase in travel cost). The above national pleasure travel demand model could be further enhanced by including monetary constraints and price variation as in the first task. Overall, the model system proposed in this dissertation forms the foundation for a national comprehensive long distance travel model. This could be achieved through inclusion of other prominent travel purpose such as business and commuting to the national travel demand model presented in this research.

<p>Emergency services (ES) pilots operate in a dynamic, high-risk team environment, as a subset of general aviation (GA) operations. The time constraints associated with ES operations means that ES pilots must make flight decisions quickly and often with limited or incomplete information (Worm, 1999). Due to the nature of ES operations, the consequences of an incorrect flight decision can be severe, including loss of life. ES operations are often initiated by extreme weather events, and ES pilots are frequently required to fly on the boundary between marginal visual flight rules (MVFR) weather conditions and instrument meteorological conditions (IMC). Unfortunately, an unintended transition into IMC is the leading cause of fatal accidents in GA operations (Ayiei et al., 2020). Mission objectives dictate that most ES pilots fly below 1,500’ above ground level (AGL) for extended periods of time, and low-altitude flight in hazardous weather can reduce a pilot’s outside visual reference, thus leading to spatial disorientation, loss of control, or controlled flight into terrain. To mitigate this problem, ES pilots must be able to accurately assess weather conditions before and during flight. However, the current method of presenting meteorological aerodrome reports (METARs) on weather displays can be misleading to pilots. Weather conditions in the areas between weather observation stations can be different than what is reported by the METAR observations at those stations. This can cause current or forecasted weather conditions <em>between</em> weather stations to be incompletely represented. However, pilots are given no obvious indication of how incompletely represented weather conditions can affect weather-related risk. This research demonstrates that a <em>Kth</em> Nearest Neighbor (KNN) analysis can be used to identify areas where the variability of conditions between weather stations (and thus weather-related risk) is incompletely represented by METAR observations. In addition, it is shown that areas where there is an increased risk of an unintended transition from MVFR to IMC can be identified among areas with incompletely represented conditions and depicted to pilots on aviation weather displays. Machine learning tactics are proposed as a way to consider additional inputs in future KNN analyses, and several emerging technologies are proposed as mediums to collect additional weather observations. The ability for an ES pilot to more accurately assess weather-related risk in MVFR conditions using the proposed technologies is evaluated, the benefits to ES pilots and the GA community are discussed, and the requirements and limitations of the study are examined.</p>

This thesis explores the Visit Friends and Relatives (VFR) tourism experiences of highly skilled first-generation Italians and Chinese in Sweden. It focuses on personal networks influence on migrant hosts’ interaction and participation in the place and how the Covid-19 global immobility has changed the dynamics and the feelings towards the place. Data are collected through semi-structured interviews with a participative target sociogram as memory recollection and visualization tool. Results showed that VFR is mainly a within network experience and the interaction with the place and the society is marginal and influenced by hosts’ mediation, their local network structure and composition. The VFR aspect of sharing quality time emerges as central element. The local dimension shapes place interaction and participation dynamics: the migrant host personal relation to the local place, their local network structure and composition, and the difference of having a native member in the network are crucial elements.

The aim of this qualitative study is to investigate the behavioral changes of family travel during a pandemic. Travels which are in focus of this study are international tourism for the purpose of leisure and VFR- travels. This study is based on the Swedish national vaccination plan from Sweden's public health authority. The study’s data is collected from ten unstructured interviews with families that have children that are younger than 17 years old. The theoretical framework of the study is Roger’s 1975 (cited in Norman, Boer and Seydel 2005) protection motivation theory, Strong’s (1990) tourists’ fear of pandemic diseases and Zheng’s et al. (2021) post-pandemic travel behavior which are used as a tool to analyze the results. The empirical data is transcribed, coded, and evaluated with the help of thematic analysis, it shows how the families behavioral changes with a pandemica. The result of this study makes it clear that the vaccination process is an important factor in the families’ travel decision-making, but it’s not a crucial factor of determination. Other aspects such as economy and legal impacts are additional side effects of the pandemic crisis which are meaningful within the families’ post-pandemic travel behavior. / Denna kvalitativa studie ämnar till att undersöka barnfamiljernas resebeteende beträffande internationella nöjesresor och BSV-resor utifrån den nationella vaccinationsplanen från Folkhälsomyndigheten. Det empiriska materialet i denna studie har insamlats genom tio ostrukturerade intervjuer där olika barnfamiljer har reflekterat över sina tankar kring resplaner, inställning till vaccin och riskbedömning gentemot COVID-19. Studiens teorier är valda på ett induktivt sätt och består av Protection Motivation Theory (Roger 1975 se Norman, Boer och Seydel 2005), Strongs (1990) tourists’ fear of pandemic diseases och Zhengs et al. (2021) post-pandemic travel behaviour. En tematisk analysmetod har applicerats för att kunna analysera de transkriberade och kodade intervjuerna. Studiens resultat påvisar att vaccination mot COVID-19 har en stor betydelse för familjern internationella och BSV- resebeslut, men erhåller inte en avgörande roll i respondenternas slutbeslut. Studien visar även ett förändrat resebeteende hos barnfamiljerna som en konsekvens av pandemins sidoeffekter på turistbranschen, exempelvis ekonomi och juridiska svårigheter och nya regler att förhålla sig till.

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