A Continuous-Time Nonlinear Observer for Estimating Structure from Motion from Omnidirectional Optic Flow

Various insect species utilize certain types of self-motion to perceive structure in their local environment, a process known as active vision. This dissertation presents the development of a continuous-time formulated observer for estimating structure from motion that emulates the biological phenomenon of active vision. In an attempt to emulate the wide-field of view of compound eyes and neurophysiology of insects, the observer utilizes an omni-directional optic flow field. Exponential stability of the observer is assured provided the persistency of excitation condition is met. Persistency of excitation is assured by altering the direction of motion sufficiently quickly. An equal convergence rate on the entire viewable area can be achieved by executing certain prototypical maneuvers. Practical implementation of the observer is accomplished both in simulation and via an actual flying quadrotor testbed vehicle. Furthermore, this dissertation presents the vehicular implementation of a complimentary navigation methodology known as wide-field integration of the optic flow field. The implementation of the developed insect-inspired navigation methodologies on physical testbed vehicles utilized in this research required the development of many subsystems that comprise a control and navigation suite, including avionics development and state sensing, model development via system identification, feedback controller design, and state estimation strategies. These requisite subsystems and their development are discussed

Breaking the Silence:Career Guidance for Self-Initiated International Placement Students”

PurposeSelf-initiated international placements by students have been largely ignored in the literature on outward mobility in higher education. The support given to self-initiated international placement students, if any, has received even less attention. This study aims to address this lacuna.Design/methodology/approachDrawing on insights from global mobility literature, we conducted a survey of UK university students who engaged in self-initiated international placements to various countries such as France, China, Brazil and Ghana. Data were analysed using descriptive statistics and thematic content analysis.FindingsFindings reveal that these “voluntary” placements can improve language fluency, increase self-confidence, renew stress management abilities and enhance cross-cultural competencies and intercultural sensitivity. The study problematises the lack of support given to these students particularly in terms of career development.Originality/valueOur paper is one of the first to bring this under-studied population to the attention of career guidance scholars. We propose that scholarly attention should be directed toward the agency of self-initiated international placement students and that targeted career guidance must be provided through more inclusive career services

Analyses of Pile Load Tests Performed on H-piles Driven into Alluvial Sands

This report describes a comprehensive pile load testing program performed on piles driven into alluvial deposits of the Mississippi River near Alton, Illinois, at the Lock and Dam 26 (Replacement) project. This investigation was made by the United State Army Engineers Oistrict, Corps of Engineers, St. Louis, Missouri.Civil Engineerin

Sensory optimisation of salt-reduced corned beef for different consumer segments

peer-reviewedThe study objectives were to determine assessors' (n = 256) preference for corned beef, produced with sequential reductions in NaCl concentrations and to determine if preference was affected by assessor age. The use of a salt replacer such as potassium lactate was also assessed. The youngest age cohort disliked samples containing the highest level of NaCl, whereas the oldest age cohort did not detect differences between samples. The most negatively perceived sample was the control, suggesting that NaCl levels added to commercial corned beef are currently too high for consumer acceptance. All age cohorts, with the exception of the 65–74 age cohort, accepted corned beef samples possessing NaCl levels closest to the FSAI target (1.63 g/100 g). No major sensory differences were noted between samples with and without potassium lactate by the ≥65 age cohort. Potassium lactate may be added to corned beef without affecting sensory attributes, whilst enhancing nutritional content. Assessors of varying age groups have differing preferences for certain NaCl levels and salt replacers

Impact on the physical and sensory properties of salt-and fat-reduced traditional Irish breakfast sausages on various age cohorts acceptance

peer-reviewedThe properties of varying salt and fat levels in traditional breakfast sausages were investigated. Sausages were produced with fat levels of: 30%, 20% and 15%. Fat was replaced with pea extract. Salt levels employed were: 2.5%, 1.1% and 0.0%. A reduced sodium salt which contains 45% less sodium than standard salt was used. Sensory analysis was conducted on consumers (n = 228): 18–40 yrs., 41–64 yrs. and 65–85 yrs. The 18–40 yr. olds preferred sausages containing 20% fat, 41–64 yr. olds preferred sausages with 15% fat, 65+ age group preferred sausages containing 30% fat. The 18–40 yr. olds preferred high salt samples, 41–64 yr. olds displayed no salt preference, while the 65+ age group preferred high salt sausages. Sausage formulation choice was found to be driven by texture for the younger age cohort, flavour for the middle age cohort and visual aspects from the oldest age cohort. There is a need to understand how meat products might be reformulated different age palates

Physics Of Eclipsing Binaries. II. Towards the Increased Model Fidelity

The precision of photometric and spectroscopic observations has been systematically improved in the last decade, mostly thanks to space-borne photometric missions and ground-based spectrographs dedicated to finding exoplanets. The field of eclipsing binary stars strongly benefited from this development. Eclipsing binaries serve as critical tools for determining fundamental stellar properties (masses, radii, temperatures and luminosities), yet the models are not capable of reproducing observed data well either because of the missing physics or because of insufficient precision. This led to a predicament where radiative and dynamical effects, insofar buried in noise, started showing up routinely in the data, but were not accounted for in the models. PHOEBE (PHysics Of Eclipsing BinariEs; http://phoebe-project.org) is an open source modeling code for computing theoretical light and radial velocity curves that addresses both problems by incorporating missing physics and by increasing the computational fidelity. In particular, we discuss triangulation as a superior surface discretization algorithm, meshing of rotating single stars, light time travel effect, advanced phase computation, volume conservation in eccentric orbits, and improved computation of local intensity across the stellar surfaces that includes photon-weighted mode, enhanced limb darkening treatment, better reflection treatment and Doppler boosting. Here we present the concepts on which PHOEBE is built on and proofs of concept that demonstrate the increased model fidelity.Comment: 60 pages, 15 figures, published in ApJS; accompanied by the release of PHOEBE 2.0 on http://phoebe-project.or

Sensory capability of young, middle-aged and elderly Irish assessors to identify beef steaks of varying texture

This study assessed the capability of various Irish assessor age cohorts to identify beef steaks of varying texture. Varying steak textures Moderately Tough (MTH), Moderately Tender (MTR) and Tender (TR) were achieved by aging beef longissimus thoracis et lumborum (LTL) muscle for 2, 7 and 21 days respectively. Warner Bratzler Shear Force (WBSF) was measured to standardise the samples. Sensory evaluation was carried using 428 participants; 18–30 yrs. (years) (n = 143), 31–60 yrs. (n = 80), 61-75 yrs. (n = 99) and 76–85 yrs. old (n = 106). Within 6 age cohort categories (18–70), significant positive and negative correlations were observed for TR and MTH tenderness categories respectively. Poor identification of tenderness classification was found in the 71–85 age cohort groupings. Consequently more research is required in this area so that guidelines could be presented for industrial uptake. This study supports the hypothesis that changes in textural perception occur with age in humans

Impact of Extended Recess: A Grounded Theory Study

Existing literature has established the benefits of recess and physical activity for children. In response, more schools in the United States (U.S.) are implementing, or even requiring, extended recess time for students. With these policy changes, it is important to understand the impact upon students, faculty, and staff. The following study used the shared experience of three elementary schools in the southern U.S. who recently implemented extended recess. Semi-structured focus groups with administrators, teachers, paraprofessionals, and students from three elementary schools were included in this pilot study. A Grounded theory approach was utilized, and findings confirmed the known benefits of recess but also enhanced understanding of the process, which included the challenges involved as well as the importance of stakeholder feedback. Recommendations are included for the professional school counselor which are applicable in both, the U.S. and internationally