Optimal Path Finding in Direction, Location and Time Dependent Environments.

This dissertation examines optimal path finding problems where cost function and constraints are direction, location and time dependent. Path-finding problems have been studied for decades in various applications; however, the published work introduces numerous assumptions to make the problem more tractable. These assumptions are often so strong as to render the model unrealistic for real life applications. In our research, we relax a number of such restrictive assumptions to create an accurate and yet tractable model suitable for implementation for a large class of problems. We first discuss optimal path finding in an anisotropic (direction-dependent), time and space homogeneous environment. We find a closed form solution for the problems with obstacle-free domain without making any assumptions on the structure of the speed function. We employ our findings to adapt a emph{visibility graph search} method of computational geometry to an anisotropic environment and deliver an optimal obstacle-avoiding path finding algorithm for a direction-dependent medium. Next, we extend our analysis to a set of problems where path curvature is constrained by a direction-dependent minimum turning radius function. We invoke techniques from optimal control theory to demonstrate the problem's controllability (by reducing the problem to Dubins car problem), prove existence of an optimal path (via Filippov's Theorem), and derive a necessary condition for optimality (using Pontryagin's Principle). Further analysis delivers a closed form characterization of an optimal path and presents an algorithm that facilitates the implementation of our results. %the solution of our problem. Finally, the assumption of time and space homogeneity is relaxed, and we develop a dynamic programming model to find an optimal path in a location, direction and time dependent environment. The results for anisotropic homogeneous environment are integrated into the model to improve its accuracy, efficiency and run-time. The path finding model addresses limited information availability, control-feasibility and computational demands of a time-dependent environment. To demonstrate the applicability and performance of our path-finding methods, computational experiments for an optimum vessel performance in evolving wave-field project are presented.Ph.D.Industrial & Operations EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/64828/1/dolira_1.pd

Higher Responsiveness of Pattern Generation Circuitry to Sensory Stimulation in Healthy Humans Is Associated with a Larger Hoffmann Reflex

Simple Summary Individual differences in the sensorimotor circuitry play an important role for understanding the nature of behavioral variability and developing personalized therapies. While the spinal network likely requires relatively rigid organization, it becomes increasingly evident that adaptability and inter-individual variability in the functioning of the neuronal circuitry is present not only in the brain but also in the spinal cord. In this study we investigated the relationship between the excitability of pattern generation circuitry and segmental reflexes in healthy humans. We found that the high individual responsiveness of pattern generation circuitries to tonic sensory input in both the upper and lower limbs was related to larger H-reflexes. The results provide further evidence for the importance of physiologically relevant assessments of spinal cord neuromodulation and the individual physiological state of reflex pathways. The state and excitability of pattern generators are attracting the increasing interest of neurophysiologists and clinicians for understanding the mechanisms of the rhythmogenesis and neuromodulation of the human spinal cord. It has been previously shown that tonic sensory stimulation can elicit non-voluntary stepping-like movements in non-injured subjects when their limbs were placed in a gravity-neutral unloading apparatus. However, large individual differences in responsiveness to such stimuli were observed, so that the effects of sensory neuromodulation manifest only in some of the subjects. Given that spinal reflexes are an integral part of the neuronal circuitry, here we investigated the extent to which spinal pattern generation excitability in response to the vibrostimulation of muscle proprioceptors can be related to the H-reflex magnitude, in both the lower and upper limbs. For the H-reflex measurements, three conditions were used: stationary limbs, voluntary limb movement and passive limb movement. The results showed that the H-reflex was considerably higher in the group of participants who demonstrated non-voluntary rhythmic responses than it was in the participants who did not demonstrate them. Our findings are consistent with the idea that spinal reflex measurements play important roles in assessing the rhythmogenesis of the spinal cord

FIGURES 105–110 in The use of egg characters for the classification of Notodontidae (Lepidoptera), with keys to the common Palaearctic genera and species

FIGURES 105–110. Eggs of Notodontidae. 105. Nerice davidi, micropylar rosette. 106. Nerice davidi, part of lateral area. 107. Nerice leechi, micropylar area. 108. Nerice leechi, part of lateral area. 109. Ptilodon capucina, micropylar area. 110. Ptilodon cucullina, micropylar area. Scale bars 105–110 (10 µ)

Optimal Path Finding in Direction, Location and Time Dependent Environments

All Rights ReservedTo my parents, who have given up so much to bring me to this country and to give me an opportunity to achieve this accomplishment. ii ACKNOWLEDGEMENTS My time in graduate school has been a very educational, exciting and challenging journey. I would like to take this opportunity to acknowledge the people who have had a positive impact on my life over the past five years and who helped me to achieve this milestone. I would like to thank my adviser, Dr. Robert L. Smith, who has been such a wonderful role model, mentor, colleague and friend. Thank you for all of your time, your numerous advice, and your refreshing perspective on things. I have always enjoyed our research meetings and conversations over coffee. Thank you to my committee members, Dr. Marina Epelman, Dr. Stephen Pollock and Dr. Jing Sun, for finding time in their busy schedules to help me at the various stages of my graduate career. Each of you have been so much more than a thesi

Transition and Regional Inequality in Russia

This paper analyzes the evolution of interregional income inequality during transition in Russia. The transition matrix approach reveals that between 1991 and 1997 income mobility tended toward a highly uneven long-term distribution with the majority of regions at low income levels and a minority of higher-income regions, in sharp contrast to pretransition times. The ordered logit analysis suggests that the more successful regions prospered on account of their natural resources, while continuing to resist economic reorganization by supporting traditional enterprises. The less-successful regions appeared trapped at low income levels due to uncompetitive industries and lack of resources needed for restructuring.Economic growth;Transition economies;Income distribution;transition period, probability, per capita income, probabilities, equation, markov chain, standard deviation, transition periods, price liberalization, transition countries, difference equation, dummy variables, sample size, surveys, time series, markov process, preliminary assessment, correlation, statistic, foreign trade, markov processes, regression analysis, stochastic process, stochastic processes, social instability, standard errors, logit analysis, outlier, frequency distributions, statistics, bargaining power, statistical tests, interest groups, probability distribution, domestic demand, survey, world market, degree of heterogeneity, scatter plot, control system, significance levels, equations, probability distributions, empirical model, sample mean, export markets

Comparative morphology on the egg chorion characters of some Noctuidae (Lepidoptera)

Dolinskaya, Irina V. (2016): Comparative morphology on the egg chorion characters of some Noctuidae (Lepidoptera). Zootaxa 4085 (3), DOI: http://doi.org/10.11646/zootaxa.4085.3.

The use of egg characters for the classification of Notodontidae (Lepidoptera), with keys to the common Palaearctic genera and species

Dolinskaya, Irina V. (2019): The use of egg characters for the classification of Notodontidae (Lepidoptera), with keys to the common Palaearctic genera and species. Zootaxa 4604 (2): 201-241, DOI: 10.11646/zootaxa.4604.2.

Larval Head Microsculpture in Palearctic Notodontidae (Noctuoidea) and Its Significance for the Systematics of the Family

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