A Preliminary Study Of Leo To Geo Transfers For Inclination Changes Using Libration Point Orbits

The required change in velocity for a satellite to change inclination has prompted studies of efficient orbital transfers. Modeling the motion of a spacecraft by including the gravitational forces associated with the Sun, Earth, and Moon has historically proven effective in obtaining new scientific knowledge. In modeling the motion of satellites, the circular restricted three body problem (CR3BP) demonstrates the interactions from two primary bodies and a satellite. The dynamics created about the equilibrium points within the CR3BP can be used to construct low-energy transfers. The invariant manifolds of the libration point orbits (LPO) can be used to create an orbit using a weak stable boundary (WSB) to approach a coplanar Lagrange point. Following the use of two distinct libration point orbits a satellite can adjust for a return at a greater difference of inclination compared to a one impulse maneuver. On approach to the second Lagrange point, the satellite follows a horizontal Lyapunov orbit to use another maneuver placing the satellite in a vertical Lyapunov orbit. Following the vertical Lyapunov orbit the weak unstable boundary is used for a return toward Earth at a different inclination. Given the trajectory created, a 90-degree inclination change has been developed. The maneuver cost is compared to a Hohmann transfer and bi-elliptic transfer for a decrease in fuel as well as an increase in the time of flight. An analysis of the periodic orbital transfer created in this research is performed, as well as other orbits from associated research articles suggest that a significant amount of velocity savings can be achieved. Continuing with the use of such constructed trajectories, a brief investigation on to financial and environmental impacts are also reviewed. The result of this study demonstrates the utility of periodic orbital transfers and their importance in mission design for plane change maneuvers

EMPLOYMENT AND POVERTY RATES OF PEOPLE WITH AND WITHOUT A COGNITIVE DISABILITY

This DataNote shares census data from the American Community Survey (ACS) that demonstrates 5-year trends in employment rates and poverty rates for working-age individuals. It compares these rates between individuals without any disabilities to individuals with a cognitive disability

Program Evaluation of The Leader in Me in a Rural Elementary School with Emphasis on Hispanic Students

The purpose of this study was to analyze the effects of The Leader in Me (TLIM) program and philosophy on a highly diverse, rural elementary school in North Carolina. TLIM is a program for school-wide transformation that seeks to teach all students 21st century leadership and life skills. TLIM is based on The 7 Habits of Highly Effective People by Covey (1989) and is an integrated approach to teaching leadership development. The study took place at School X, which has over 440 students. School X is diverse: 46% of the students are Hispanic; 41% are White; and 13% are Asian, African-American, or American Indian. School X is considered a Title I school, with 87% of its students receiving free or reduced lunch. The chosen elementary school suffered from a disjointed school culture: teachers who were ill equipped with how to meet the challenge of growing students living in poverty, student conduct issues, high teacher turnover, and a lack of a common mission or vision. The researcher analyzed both quantitative and qualitative data to answer research questions centered on school culture, effects TLIM had on student conduct, and effects on academic achievement scores. The researcher also analyzed the specific effects TLIM had on Hispanic students at School X. This research provides evidence that teaching students social-emotional skills and soft skills can impact the overall culture of a school and improve the conduct of the students. This study reveals that TLIM impacts a school’s culture regardless of race, economic status, or size. TLIM can be used to actively support educators at a school that has extremely high diversity and poverty rates

Data Note: Employment Rates for People With and Without Disabilities

Data show that people with disabilities are consistently less likely to be working than their non-disabled counterparts. In this Data Note, the employment rate for working-age people is compared across disability types, as well as those without disabilities

Public Policy Incentives for Large-Scale Dairies in Georgia

Declining dairy cow populations in Georgia at a time when the human population is increasing lead to changes in the milk marketing system. A public policy initiative from state government to increase the number of large-scale dairies in Georgia has the potential to increase economic activity throughout the state. Total state output impact of a 1,000-head dairy farm in Georgia is $7.854 million, including$4.256 million in indirect economic activity. Although the agricultural sector receives the greatest benefits of dairy production, other sectors have significant sales and employment from milk production. Fluid milk manufacturing is an enterprise separate from production that has a state-level output impact of $9.844 million for a dairy farm with 1,000 milk cows. Results show there are economic development incentives for states to adopt public policies which can affect milk distribution and marketing in the Southeast.Agricultural and Food Policy, Livestock Production/Industries,

The Economic Cost of Domestic Hunger: Estimated Annual Burden to the United States

Examines the extent of domestic hunger and estimates the cost burden of food insecurity to the nation, including the costs of charity to help feed families, mental health and physical illnesses, and impaired educational outcomes and economic productivity

A Framework for Collaborative Multi-task, Multi-robot Missions

Robotics is a transformative technology that will empower our civilization for a new scale of human endeavors. Massive scale is only possible through the collaboration of individual or groups of robots. Collaboration allows specialization, meaning a multirobot system may accommodate heterogeneous platforms including human partners. This work develops a unified control architecture for collaborative missions comprised of multiple, multi-robot tasks. Using kinematic equations and Jacobian matrices, the system states are transformed into alternative control spaces which are more useful for the designer or more convenient for the operator. The architecture allows multiple tasks to be combined, composing tightly coordinated missions. Using this approach, the designer is able to compensate for non-ideal behavior in the appropriate space using whatever control scheme they choose. This work presents a general design methodology, including analysis techniques for relevant control metrics like stability, responsiveness, and disturbance rejection, which were missing in prior work. Multiple tasks may be combined into a collaborative mission. The unified motion control architecture merges the control space components for each task into a concise federated system to facilitate analysis and implementation. The task coordination function defines task commands as functions of mission commands and state values to create explicit closed-loop collaboration. This work presents analysis techniques to understand the effects of cross-coupling tasks. This work analyzes system stability for the particular control architecture and identifies an explicit condition to ensure stable switching when reallocating robots. We are unaware of any other automated control architectures that address large-scale collaborative systems composed of task-oriented multi-robot coalitions where relative spatial control is critical to mission performance. This architecture and methodology have been validated in experiments and in simulations, repeating earlier work and exploring new scenarios and. It can perform large-scale, complex missions via a rigorous design methodology