The Long Wind of Change. Educational Impacts on Entrepreneurial Intentions

In this paper, we assess educational factors which might have an impact on entrepreneurship. We analyze influences on the entrepreneurial intentions of German university students and find that pre-university education significantly affects their desire to become an entrepreneur. Using the recent German history of separation and reunification as quasi-natural experiment, we focus on the early formation of entrepreneurial endowments during adolescence and investigate whether pre-university education affects university students’ entrepreneurial intentions. Particularly, we analyze the impact of socialization and schooling under the socialist regime of the former German Democratic Republic (GDR) which might hamper entrepreneurship. Our results show that socialist education has a negative effect on the entrepreneurial intentions of students in reunified Germany who were brought up in the GDR. When analyzing the subsample of East German students who were partly educated in the FRG after reunification in 1990, we find that some years of education in the liberal market system increase the entrepreneurial intentions of students born in the GDR. We focus on university students, since universities are seen as potential “breeding ground†for innovative entrepreneurship as described by Schumpeter (1912). Here we assume according to Falck et al. (2009) that entrepreneurial intentions are a good predictor for future entrepreneurship. We use data from a regularly repeated survey among university students in Germany. Our analysis rests on the three waves conducted after reunification at 23 universities, in (the former socialist) East as well as in West Germany. Generally, German students have significantly lower entrepreneurial intentions when they were educated in the GDR. We further restrict our sample to mobile students at West German universities and still find a negative effect of socialist education. This effect is also robust to the inclusion of a rich set of control variables concerning the students’ family background, job experience as well as further measures for their educational training. Overall, being educated in the socialist GDR decreases the likelihood of having entrepreneurial intentions between around 4 and 7 percentage points Thus our findings suggest that adolescents’ education might act as effective measure to stimulate entrepreneurship.

Implicit Formulations of Bounded-Impulse Trajectory Models for Preliminary Interplanetary Low-Thrust Analysis

The bounded-impulse approach to low-thrust interplanetary trajectory optimization is widely used. In an effort to efficiently implement this approach using NASAs OpenMDAO optimization software, the authors have implemented implicit formulations of the forward shooting/backwards-shooting methods commonly used in bounded-impulse models. These implicit approaches allow for vectorization of the underlying calculations which can significantly reduce runtime in interpreted languages. An implicit approach may be either converged by using an underlying nonlinear solver to converge the state propagation, or as a constraint in an optimizer-driven multiple-shooting approach. Significant computational efficiency gains are realized through the utilization of the modular approach to unified derivatives. Further computational efficiency is achieved by capitalizing on the sparsity of the constraint Jacobian matrix. This work demonstrates that a vectorized multiple-shooting approach for propagating a state-time history is superior in terms of computational efficiency as the number of segments in the state-propagation is increased

E-Lections: Voting Behavior and the Internet

This paper analyses the effect of information disseminated by the Internet on voting behavior. We address endogeneity in Internet availability by exploiting regional and technological peculiarities of the preexisting voice telephony network that hinder the roll-out of fixed-line broadband infrastructure for high-speed Internet. We find small negative effects of Internet availability on voter turnout, and no evidence that the Internet systematically benefits single parties. Robustness tests including placebo estimations from the pre-Internet era confirm our results. We relate differences in the Internet effect between national and local elections to a crowding out of national but not local newspapers

Optimal Control within the Context of Multidisciplinary Design, Analysis, and Optimization

Multidisciplinary design, analysis and optimization involves modeling the interactions of complex systems across a variety of disciplines. The optimization of such systems can be a computationally expensive exercise with multiple levels of nested nonlinear solvers running under an optimizer.The application of optimal control in project development often involves performing trajectory optimization for fixed vehicle designs or parametric sweeps across some key vehicle properties.This information is then relayed to the subsystem design teams who update their designs and relay some bulk characteristics back to the trajectory optimization procedure.This iteration is then repeated until the design closes.However, with increasing interest in more tightly coupled systems, such as electric and hybrid-electric aircraft propulsion and boundary layer ingestion, this process is prone to ignore subtle coupling between vehicle subsystem designs and vehicle operation on a given mission.Integrating trajectory optimization into a tightly coupled multidisciplinary design procedure can be computationally prohibitive, depending on the complexity of the subsystem analyses and the optimal control technique applied.To address these issues a new optimal control software tool, Dymos, has been developed.Dymos is built upon NASA's OpenMDAO software and can leverage its capabilities to efficiently compute gradients for the optimization and optimize complex models in parallel on distributed memory systems.This report provides some explanation into the numerical methods employed in Dymos and provides several use cases that demonstrate its performance on traditional optimal control problems and improvements ino techniques have been used extensively in recent decades to solve a variety of optimal control problems, typically in the form of aerospace vehicle trajectory optimization

Optimization of Low-Thrust Spiral Trajectories by Collocation

As NASA examines potential missions in the post space shuttle era, there has been a renewed interest in low-thrust electric propulsion for both crewed and uncrewed missions. While much progress has been made in the field of software for the optimization of low-thrust trajectories, many of the tools utilize higher-fidelity methods which, while excellent, result in extremely high run-times and poor convergence when dealing with planetocentric spiraling trajectories deep within a gravity well. Conversely, faster tools like SEPSPOT provide a reasonable solution but typically fail to account for other forces such as third-body gravitation, aerodynamic drag, solar radiation pressure. SEPSPOT is further constrained by its solution method, which may require a very good guess to yield a converged optimal solution. Here the authors have developed an approach using collocation intended to provide solution times comparable to those given by SEPSPOT while allowing for greater robustness and extensible force models

Practical Student Self-affirmation

This research paper focuses on student peer interactional relationships in a tertiary level classroom setting in Japan. The research is based on the use of one piece of technology, Microsoft PowerPoint, to illustrate student peer interactional relationships during presentation tasks throughout the 2015 Spring Semester. The application of the particular software used in this research is of little importance, in that any piece of software could be used to investigate student interaction. The important findings of this research indicate that students can be made aware of their self-affirmation through an application of sociolinguistics and an introduction of critical pedagogy that encompasses a significant reduction in the influence of the traditional ‘teacher’ role to the benefit of student empowerment. The role of the student changes from being the passive object to that of a more active Subject role, as that of the ‘teacher,’ or better termed ‘facilitator,’ dispenses their traditional paternalistic, authoritative Subject position, in favor of being one that helps to bring about ‘…an outcome (as learning, productivity, or communication) by providing indirect or unobtrusive assistance, guidance, or supervision,’ on the part of the ‘facilitator,’ as it is defined in the Miriam-Webster dictionary (2015). For students to adopt a more active role requires a change in study habits, which requires more effort. However, this adheres perfectly to the Kyoai College motto; ‘You can develop your ability though it might be hard’ (Kyoai, 2015)

Application of Modern Fortran to Spacecraft Trajectory Design and Optimization

In this paper, applications of the modern Fortran programming language to the field of spacecraft trajectory optimization and design are examined. Modern object-oriented Fortran has many advantages for scientific programming, although many legacy Fortran aerospace codes have not been upgraded to use the newer standards (or have been rewritten in other languages perceived to be more modern). NASA's Copernicus spacecraft trajectory optimization program, originally a combination of Fortran 77 and Fortran 95, has attempted to keep up with modern standards and makes significant use of the new language features. Various algorithms and methods are presented from trajectory tools such as Copernicus, as well as modern Fortran open source libraries and other projects

Comparison of Low-Thrust Control Laws for Application in Planetocentric Space

Recent interest at NASA for the application of solar electric propulsion for the transfer of significant payloads in cislunar space has led to the development of high-fidelity simulations of such missions. With such transfers involving transfer times on the order of months, simulation time can be significant. In the past, the examination of such missions typically began with the use of lower-fidelity trajectory optimization tools such as SEPSPOT to develop and tune guidance laws which delivered optimal or near- optimal trajectories, where optimal is generally defined as minimizing propellant expenditure or time of flight. The transfer of these solutions to a high-fidelity simulation is typically an iterative process whereby the initial solution may nearly, but not precisely, meet mission objectives. Further tuning of the guidance algorithm is typically necessary when accounting for high-fidelity perturbations such as those due to more detailed gravity models, secondary-body effects, solar radiation pressure, etc. While trajectory optimization is a useful method for determining optimal performance metrics, algorithms which deliver nearly optimal performance with minimal tuning are an attractive alternative

A Flexible Path for Human and Robotic Space Exploration

During the summer of 2009, a flexible path scenario for human and robotic space exploration was developed that enables frequent, measured, and publicly notable human exploration of space beyond low-Earth orbit (LEO). The formulation of this scenario was in support of the Exploration Beyond LEO subcommittee of the Review of U.S. Human Space Flight Plans Committee that was commissioned by President Obama. Exploration mission sequences that allow humans to visit a wide number of inner solar system destinations were investigated. The scope of destinations included the Earth-Moon and Earth-Sun Lagrange points, near-Earth objects (NEOs), the Moon, and Mars and its moons. The missions examined assumed the use of Constellation Program elements along with existing launch vehicles and proposed augmentations. Additionally, robotic missions were envisioned as complements to human exploration through precursor missions, as crew emplaced scientific investigations, and as sample gathering assistants to the human crews. The focus of the flexible path approach was to gain ever-increasing operational experience through human exploration missions ranging from a few weeks to several years in duration, beginning in deep space beyond LEO and evolving to landings on the Moon and eventually Mars

Multidisciplinary Optimization of Urban-Air-Mobility Class Aircraft Trajectories with Acoustic Constraints

The design and analysis of on-demand mobility class vehicles will require thorough acoustic analysis to ensure that more numerous aircraft can operate in densely populated areas without causing excessive levels of noise. This work is a step towards a comprehensive ODM vehicle analysis capability. The authors use 6DOF equations of motion to model the electric quad-rotor concept developed by NASA's Revolutionary Vertical Lift Technologies program. As a first step towards acoustic analysis, this trajectory is coupled to an acoustic model that tracks the sound pressure level perceived by an acoustic observer on the ground. The results show that the approach is successful in finding trajectories that minimize total propulsive impulse while obeying limits imposed on the sound pressure level. Future work will involve adding acoustic analysis of increasing fidelity and tying the resulting trajectories to the performance of the electric propulsion system