Aerial Map-Based Navigation Using Semantic Segmentation and Pattern Matching

This paper proposes a novel approach to map-based navigation system for unmanned aircraft. The proposed system attempts label-to-label matching, not image-to-image matching between aerial images and a map database. By using semantic segmentation, the ground objects are labelled and the configuration of the objects is used to find the corresponding location in the map database. The use of the deep learning technique as a tool for extracting high-level features reduces the image-based localization problem to a pattern matching problem. This paper proposes a pattern matching algorithm which does not require altitude information or a camera model to estimate the absolute horizontal position. The feasibility analysis with simulated images shows the proposed map-based navigation can be realized with the proposed pattern matching algorithm and it is able to provide positions given the labelled objects.Comment: 6 pages, 4 figure

First detection of 22 GHz H2O masers in TX Camelopardalis

Simultaneous time monitoring observations of H$_{2}$O $6_{16}-5_{23}$, SiO $J$ = 1--0, 2--1, 3--2, and $^{29}$SiO $v$ = 0, $J$ = 1--0 lines were carried out in the direction of the Mira variable star TX Cam with the Korean VLBI Network single dish radio telescopes. For the first time, the H$_{2}$O maser emission from TX Cam was detected near the stellar velocity at five epochs from April 10, 2013 ($\phi$ = 3.13) to June 4, 2014 ($\phi$ = 3.89) including minimum optical phases. The intensities of H$_{2}$O masers are very weak compared to SiO masers. The variation of peak antenna temperature ratios among SiO $v$ = 1, $J$ = 1--0, $J$ = 2--1, and $J$ = 3--2 masers is investigated according to their phases. The shift of peak velocities of H$_{2}$O and SiO masers with respect to the stellar velocity is also investigated according to observed optical phases. The H$_{2}$O maser emission occurs around the stellar velocity during our monitoring interval. On the other hand, the peak velocities of SiO masers show a spread compared to the stellar velocity. The peak velocities of SiO $J$ = 2--1, and $J$ = 3--2 masers show a smaller spread with respect to the stellar velocity than those of SiO $J$ = 1--0 masers. These simultaneous observations of multi-frequencies will provide a good constraint for maser pumping models and a good probe for investigating the stellar atmosphere and envelope according to their different excitation conditions.Comment: 10 page

Introduction to Kalman Filter and Its Applications

We provide a tutorial-like description of Kalman filter and extended Kalman filter. This chapter aims for those who need to teach Kalman filters to others, or for those who do not have a strong background in estimation theory. Following a problem definition of state estimation, filtering algorithms will be presented with supporting examples to help readers easily grasp how the Kalman filters work. Implementations on INS/GNSS navigation, target tracking, and terrain-referenced navigation (TRN) are given. In each example, we discuss how to choose, implement, tune, and modify the algorithms for real world practices. Source codes for implementing the examples are also provided. In conclusion, this chapter will become a prerequisite for other contents in the book

Satellite Constellation Orbit Design Optimization with Combined Genetic Algorithm and Semianalytical Approach

This paper focuses on maximizing the percent coverage and minimizing the revisit time for a small satellite constellation with limited coverage. A target area represented by a polygon defined by grid points is chosen instead of using a target point only. The constellation consists of nonsymmetric and circular Low Earth Orbit (LEO) satellites. A global optimization method, Genetic Algorithm (GA), is chosen due to its ability to locate a global optimum solution for nonlinear multiobjective problems. From six orbital elements, five elements (semimajor axis, inclination, argument of perigee, longitude of ascending node, and mean anomaly) are varied as optimization design variables. A multiobjective optimization study is conducted in this study with percent coverage and revisit time as the two main parameters to analyze the performance of the constellation. Some efforts are made to improve the objective function and to minimize the computational load. A semianalytical approach is implemented to speed up the guessing of initial orbital elements. To determine the best parametric operator combinations, the fitness value and the computational time from each study cases are compared

Determinants of Unintended Pregnancy and Modern Family Planning Use

Unintended pregnancy, defined as a pregnancy that is mistimed or unwanted, is one of the world’s most common negative health outcomes. Furthermore, the United Nations Population Fund has found that 225 million women wish to delay or avoid pregnancy yet do not engage in modern family planning method use. Unintended pregnancy affects both maternal health (by way of nutrient deficiency, reproductive organ deficiency, and mental health) and child health (low birth weight, reduced gestational age, and nursing difficulties). The most life-saving and cost-saving means to prevent unintended pregnancy is to encourage modern family planning use. This dissertation examines family planning and unintended pregnancy in three different national contexts. In these studies, I: 1. Decompose the differences in unintended pregnancy rates for black and Hispanic women compared to white women in the United States; 2. Examine the relationship among indicators of health literacy, health system access, and utilization of modern family planning in Senegal; 3. Evaluate an intervention in Benin designed to increase modern family planning use. My research found that black and Hispanic women had a greater likelihood of unintended pregnancy compared to white women. However, psychosocial and socioeconomic factors contributed to the greater likelihoods of unintended pregnancy among racial and ethnic minorities. Among indicators of health literacy, oral and visual messages were the strongest predictors of health system access and modern family planning use in Senegal. The conclusion of the intervention in Benin found that social diffusion behaviors increased among people in the treatment group, and furthermore, the intervention did reduce unmet need for modern family planning use. These research results, though from different research studies, can imply that increasing access as much as possible to modern family planning use can ultimately prevent unintended pregnancy