Air Vehicle Path Planning

This dissertation explores optimal path planning for air vehicles. An air vehicle exposed to illumination by a tracking radar is considered and the problem of determining an optimal planar trajectory connecting two prespecified points is addressed. An analytic solution yielding the trajectory minimizing the received radar energy reflected from the target is derived using the Calculus of Variations. Additionally, the related problem of an air vehicle tracked by a passive sensor is also solved. Using the insights gained from the single air vehicle radar exposure minimization problem, a hierarchical cooperative control law is formulated to determine the optimal trajectories that minimize the cumulative exposure of multiple air vehicles during a rendezvous maneuver. The problem of one air vehicle minimizing exposure to multiple radars is also addressed using a variational approach, as well as a sub-optimal minimax argument. Local and global optimality issues are explored. A novel decision criterion is developed determining the geometric conditions dictating when it is preferable to go between or around two radars. Lastly, an optimal minimum time control law is obtained for the search and target identification mission of an autonomous air vehicle. This work demonstrates that an awareness of the consequences of embracing sub-optimal and non-globally optimal solutions for optimization problems, such as air vehicle path planning, is essential

A conductor\u27s study of Ruth Watson Henderson\u27s Voices of Earth

Ruth Watson Henderson (b. 1932) has become one of Canada’s most prolific composers. She began her music study at a very early age and her career as a performer prospered as she received many awards and honors throughout her life. Her accomplishments as a performer and composer are numerous. Her work as the accompanist for the Toronto Children’s Choir has led to many pieces for children’s voices, and her involvement in church music as an organist has resulted in many sacred compositions for mixed choir. This research presents a brief biographical introduction of Ruth Watson Henderson and a conductor’s analysis of Voices of Earth. One of Henderson’s most significant compositions, its original version is scored for three choruses and two pianos. The three choral ensembles are a mixed chamber choir, a mixed large chorus, and a children’s choir. It is also available with orchestral accompaniment, the version used for this research. Voices of Earth is a 25 minute piece with text taken from writings attributed to St. Francis and from the poems of the Canadian poet Archibald Lampman (1861-1899) whose works were prominent in Canada during the second half of the 19th century. The choral works of Ruth Watson Henderson and her Voices of Earth demonstrate her ability to fuse the elements of text and music into an artistic creation which is worthy of performance. Awareness and analysis of noteworthy compositions such as this one brings about a vital connection between composer and conductor that enhances the performance. Understanding the analysis of performance preparation and score study only strengthens the relationship between performer and composer. The role of analysis is to gain insight into the piece itself and to bring about a meaningful interpretation of the composer’s intentions. The goal of this research will bring about this important aspect of analysis and expose the profession to the work of a notable composer

Velocity Determination for an Inverted Pseudolite Navigation Reference System

As navigation systems continue to improve in performance and features, the Air Force must develop better Navigation Reference Systems (NRS) to keep pace with technology. Specifically, with the advent of enhanced, integrated Global Positioning System (GPS) and Inertial Navigation System (INS) navigators, emphasis is placed on the measuring performance in the presence of GPS jamming. To meet these needs, a new NRS, dubbed the Sub-Meter Accuracy Reference System (SARS), is being developed by the 746th Test Squadron, Holloman AFB, New Mexico. SARS uses a unique, inverted GPS pseudolite positioning system to determine a reference trajectory. This research investigates two post processing methods of determining velocity from a discrete position data at a constant data rate. The first method employs numerical differentiation along with digital filters provide noise reduction. The second method uses kinematic model based Kalman filter and smoothing to determine the reference velocity

Attitudes of non-practicing chiropractors: a pilot survey concerning factors related to attrition

Background Research into attitudes about chiropractors who are no longer engaged in active clinical practice is non-existent. Yet non-practicing chiropractors (NPCs) represent a valid sub-group worthy of study. Aim The purpose of this research was to assess attrition attitudes of NPCs about the chiropractic profession and develop a scale to assess such attitudes. Methods A 48 item survey was developed using the PsychData software. This survey included 35 Likert-style items assessing various aspects of the profession namely financial, educational, psychosocial and political. An internet discussion site where NPCs may be members was accessed for recruitment purposes. Results A total of 70 valid responses were received for analysis. A majority of respondents were male with 66% being in non-practice status for 3 to 5 years and less with 43% indicating that they had graduated since the year 2000. Most respondents were employed either in other healthcare professions and non-chiropractic education. A majority of NPCs believed that business ethics in chiropractic were questionable and that overhead expense and student loans were factors in practice success. A majority of NPCs were in associate practice at one time with many believing that associates were encouraged to prolong the care of patients and that associate salaries were not fair. Most NPCs surveyed believed that chiropractic was not a good career choice and would not recommend someone to become a chiropractor. From this survey, a 12 item scale was developed called the "chiropractor attrition attitude scale" for future research. Reliability analysis of this novel scale demonstrated a coefficient alpha of 0.90. Conclusion The low response rate indicates that findings cannot be generalized to the NPC population. This study nonetheless demonstrates that NPCs attrition attitudes can be assessed. The lack of a central database of NPCs is a challenge to future research. Appropriate investigation of attrition within the chiropractic profession would be helpful in the analysis of attitudes regarding both chiropractic education and practice. Further research is needed in this area

Autonomy Infused Teleoperation with Application to BCI Manipulation

Robot teleoperation systems face a common set of challenges including latency, low-dimensional user commands, and asymmetric control inputs. User control with Brain-Computer Interfaces (BCIs) exacerbates these problems through especially noisy and erratic low-dimensional motion commands due to the difficulty in decoding neural activity. We introduce a general framework to address these challenges through a combination of computer vision, user intent inference, and arbitration between the human input and autonomous control schemes. Adjustable levels of assistance allow the system to balance the operator's capabilities and feelings of comfort and control while compensating for a task's difficulty. We present experimental results demonstrating significant performance improvement using the shared-control assistance framework on adapted rehabilitation benchmarks with two subjects implanted with intracortical brain-computer interfaces controlling a seven degree-of-freedom robotic manipulator as a prosthetic. Our results further indicate that shared assistance mitigates perceived user difficulty and even enables successful performance on previously infeasible tasks. We showcase the extensibility of our architecture with applications to quality-of-life tasks such as opening a door, pouring liquids from containers, and manipulation with novel objects in densely cluttered environments

Fulminant meningococcal supraglottitis: An emerging infectious syndrome?

We report a case of fulminant supraglottitis with dramatic external cervical swelling due to associated cellulitis. Blood cultures were positive for Neisseria meningitidis. The patient recovered completely after emergency fiberoptic intubation and appropriate antibiotic therapy. We summarize five other cases of meningococcal supraglottitis, all reported since 1995, and discuss possible pathophysiologic mechanisms

The effect of the inclusion of trunk-strengthening exercises to a multimodal exercise program on physical activity levels and psychological functioning in older adults: secondary data analysis of a randomized controlled trial

Background: Engaging in multimodal exercise program helps mitigate age-related decrements by improving muscle size, muscle strength, balance, and physical function. The addition of trunk-strengthening within the exercise program has been shown to significantly improve physical functioning outcomes. Whether these improvements result in improved psychological outcomes associated with increased physical activity levels requires further investigation. We sought to explore whether the inclusion of trunk-strengthening exercises to a multimodal exercise program improves objectively measured physical activity levels and self-reported psychological functioning in older adults. Method: We conducted a secondary analysis within a single-blinded parallel-group randomized controlled trial. Sixty-four healthy older (≥ 60 years) adults were randomly allocated to a 12-week walking and balance exercise program with (n = 32) or without (n = 32) inclusion of trunk strengthening exercises. Each program involved 12 weeks of exercise training, followed by a 6-week walking-only program (identified as detraining). Primary outcome measures for this secondary analysis were physical activity (accelerometry), perceived fear-of-falling, and symptoms of anxiety and depression. Results: Following the 12-week exercise program, no significant between-group differences were observed for physical activity, sedentary behaviour, fear-of-falling, or symptoms of anxiety or depression. Significant within-group improvements (adjusted mean difference [95%CI]; percentage) were observed in moderate-intensity physical activity (6.29 [1.58, 11.00] min/day; + 26.3%) and total number of steps per min/day (0.81 [0.29 to 1.33] numbers or + 16.3%) in trunk-strengthening exercise group by week 12. With respect to within-group changes, participants in the walking-balance exercise group increased their moderate-to-vigorous physical activity (MVPA) (4.81 [0.06 to 9.56] min/day; + 23.5%) and reported reduction in symptoms of depression (-0.26 [-0.49 to -0.04] points or -49%) after 12 weeks of the exercise program. The exercise-induced increases in physical activity levels in the trunk-strengthening exercise group were abolished 6-weeks post-program completion. While improvements in physical activity levels were sustained in the walking-balance exercise group after detraining phase (walking only). Conclusions: The inclusion of trunk strengthening to a walking-balance exercise program did not lead to statistically significant between-group improvements in physical activity levels or psychological outcomes in this cohort following completion of the 12-week exercise program. Trial registration: Australian and New Zealand Clinical Trials Registry (ACTRN12613001176752), registered on 28/10/2013

The Cancer Prevention and Control Research Network

The Cancer Prevention and Control Research Network is a national network recently established to focus on developing new interventions and disseminating and translating proven interventions into practice to reduce cancer burden and disparities, especially among minority and medically underserved populations. Jointly funded by the Centers for Disease Control and Prevention and the National Cancer Institute, the Cancer Prevention and Control Research Network consists of sites administered through Prevention Research Centers funded by the Centers for Disease Control and Prevention. The five sites are located in Kentucky, Massachusetts, South Carolina, Texas, Washington State, and West Virginia. The Cancer Prevention and Control Research Network's intervention areas include primary prevention of cancer through healthy eating, physical activity, sun avoidance, tobacco control, and early detection of cancer through screening. The Cancer Prevention and Control Research Network uses the methods of community-based participatory research and seeks to build on the cancer-relevant systematic reviews of the Guide to Community Preventive Services. Initial foci for the Cancer Prevention and Control Research Network's research work groups include projects to increase screening for breast, cervical, and colorectal cancers; to promote informed decision making for prostate cancer screening; and to validate educational materials developed for low-literacy populations

Correction to: Bilingualism is associated with a delayed onset of dementia but not with a lower risk of developing it: A systematic review with meta-analyses

The original version of this article unfortunately contained the following mistakes. 1. In the Results section under the paragraph Disease Severity, the sentence “The PIs ranged between -0.47 and 0.57 MMSE points” should read -0.49 and 0.59 MMSE points. 2. In Figs. 3, 5, and 7, the labels “favour bilinguals” and “favours monolinguals” should be inverted. Therefore, it should be “favours monolinguals” and “favours bilinguals”. Please see below for the correct figures. © 2020, The Author(s)

Food Distribution and Consumption in Knoxville: Exploring Food-Related Local Planning Issues

Summary: City planners have traditionally made an effort to understand the interrelationships between urban activities and various support systems, such as transportation, water and sewer, waste management, communications and energy. Food is also an important urban support system with a complex system of supply, distribution, and consumption. An understanding of the nature of the food supply and distribution system seems important, but in the past has not been an area of concern for the planning profession. It was the intent of this project to develop a basis from which to seek an understanding of the Knoxville food support system and its implications for local planning policy in Knoxville. The thrust of the study was three-fold. First, food-related problems and issues were identified. Then, further work was undertaken in order to propose remedial measures or public programs that might be initiated by local units of government. Finally, the group considered the possibility of establishing some kind of public oversight of the local food supply and distribution function. The approach has been general and comprehensive. One assumption here is that before public action can be initiated, those with responsibility for maintaining the public interest must understand the system. Thus, an analysis which would describe the system comprehensively, while allowing an opportunity to detect interrelationships among system components, was utilized. Patterns of consumption, food services and programs, and marketing channels by food types were also explored. The development of information involves consultation with literature, academicians, public officials, and industry representatives