GPS vertical axis performance enhancement for helicopter precision landing approach

Several areas were investigated for improving vertical accuracy for a rotorcraft using the differential Global Positioning System (GPS) during a landing approach. Continuous deltaranging was studied and the potential improvement achieved by estimating acceleration was studied by comparing the performance on a constant acceleration turn and a rough landing profile of several filters: a position-velocity (PV) filter, a position-velocity-constant acceleration (PVAC) filter, and a position-velocity-turning acceleration (PVAT) filter. In overall statistics, the PVAC filter was found to be most efficient with the more complex PVAT performing equally well. Vertical performance was not significantly different among the filters. Satellite selection algorithms based on vertical errors only (vertical dilution of precision or VDOP) and even-weighted cross-track and vertical errors (XVDOP) were tested. The inclusion of an altimeter was studied by modifying the PVAC filter to include a baro bias estimate. Improved vertical accuracy during degraded DOP conditions resulted. Flight test results for raw differential results excluding filter effects indicated that the differential performance significantly improved overall navigation accuracy. A landing glidepath steering algorithm was devised which exploits the flexibility of GPS in determining precise relative position. A method for propagating the steering command over the GPS update interval was implemented

The application of NAVSTAR Differential GPS to civil helicopter operations

Principles concerning the operation of the NAVSTAR Global Positioning Systems (GPS) are discussed. Selective availability issues concerning NAVSTAR GPS and differential GPS concepts are analyzed. Civil support and market potential for differential GPS are outlined. It is concluded that differential GPS provides a variation on the baseline GPS system, and gives an assured, uninterrupted level of accuracy for the civilian community

False Endorsement or First Amendment?: An Analysis of Celebrity Trademark Rights and Artistic Expression

In Part I, this Comment will address both artistic and entertainment industry issues relating to using celebrity names and images in creative works. Part II will discuss the relationship between state right of publicity and privacy claims, and federal trademark law. Part III will discuss the Lanham Act\u27s history and purpose, including its traditional applications and recent amendments. Part IV will address the First Amendment issues raised when creative works use celebrities\u27 names and images. Part V will address the three tests courts use to balance section 43(a) Lanham Act claims and First Amendment rights. Part VI will advocate the consistent use of the Rogers test as a low threshold to remove artistic works from the trademark regulation regime

Local Processes of Homophone Acquisition

The Naive Generalization Model (NGM) (Caplan, 2018) explains word learning phenomena as grounded in the local, dynamical process of category formation. A range of experimental evidence (Xu and Tenenbaum, 2007; Spencer et al., 2011; Lewis and Frank, 2018) supports the NGM over prior models of word learning such as Bayesian inference (Xu and Tenenbaum, 2007). Despite such progress, a number of theoretical phenomena remain unaddressed by previous accounts. In this paper, we present a novel extension to NGM which offers a strong fit to and explanation of experimental data on homophone acquisition (Dautriche et al., 2016)

Fast and circular fashion: a comparison on sustainability of two fashion retail business models

Treballs Finals del Grau d'Empresa Internacional, Facultat d'Economia i Empresa, Universitat de Barcelona, Curs: 2020-2021 , Tutor: Mònica Serrano[eng]The topic of fashion and sustainability is nowadays very salient thanks to organizations like the Ellen MacArthur Foundation or Greenpeace. Social movements like Greta Thunberg’s Fridays for future or the #PayUp campaign have also been key to make society conscious of the social and environmental impacts of the fashion industry, mainly caused by the fast fashion business model of many retailers and fashion companies. The complexity of the link between fashion and sustainability leads to the following research questions: Is the fashion industry as we know it today sustainable? Which are the similarities and differences in terms of sustainability of fashion retail companies with a fast fashion business model and fashion retail companies with a business model related to the circular economy? The theoretical part of this Final Degree Project, which presents the Global Value Chain of the fashion industry, sustainability, and the concept of circular economy, provides the tools to understand the sustainability status-quo of the fashion industry. In the applied part of the project, we compare the fashion retailers Kiabi and Percentil from a business perspective, and in terms of sustainability, to understand how they resemble and differ from each other.[cast] El tema de la moda y la sostenibilidad es muy relevante actualmente gracias a organizaciones como the Ellen MacArthur Foundation o Greenpeace. Los movimientos sociales como Fridays for future de Greta Thunberg, o la campaña #PayUp también han sido claves para concienciar a la sociedad del impacto social y medioambiental de la industria de la moda, principalmente causado por el modelo de negocio de moda rápida que emplean muchas compañías minoristas de moda. La compleja relación entre la moda y la sostenibilidad lleva a las siguientes preguntas de investigación: ¿La industria de la moda de hoy en día es sostenible? ¿Cuáles son las similitudes y diferencias, en términos de sostenibilidad, de compañías minoristas con un modelo de negocio de moda rápida, y de compañías minoristas de moda con un modelo de empresa relacionado con la economía circular? La parte teórica de este Trabajo de Final de Grado, que presenta la Cadena de Valor Mundial de la industria de la moda, la sostenibilidad, y la economía circular nos da las herramientas para entender el status-quo de la sostenibilidad de la industria de la moda. En la parte práctica del trabajo se compara a Kiabi y a Percentil desde una perspectiva empresarial y de sostenibilidad para entender en qué puntos se parecen y en cuales son distintos

Polarization Spectroscopy and Collisions in NaK

We report current work to study transfer of population and orientation in collisions of NaK molecules with argon and potassium atoms using polarization labeling (PL) and laser-induced fluorescence (LIF) spectroscopy. In the PL experiment, a circularly polarized pump laser excites a specific NaK A1Σ +(v=16, J) ← X1Σ +(v=0, J ± 1) transition, creating an orientation (non-uniform MJ level distribution) in both levels. The linear polarized probe laser is scanned over various 3 1Π(v=8, J 0 ± 1) ← A1Σ +(v=16, J 0 ) transitions. The probe laser passes through a crossed linear polarizer before detection, and signal is recorded if the probe laser polarization has been modified by the vapor (which occurs when it comes into resonance with an oriented level). In addition to strong direct transitions (J 0 = J), we also observe weak collisional satellite lines (J 0 = J ±n with n = 1, 2, 3, ...) indicating that orientation is transferred to adjacent rotational levels during a collision. An LIF experiment (with linear polarized pump and probe beams) gives information on the collisional transfer of population. From these data, cross sections for both processes can be determined. We experimentally distinguish collisions of NaK with argon atoms from collisions with alkali atoms

Collisional Transfer of Population and Orientation in NaK

We report current work to study transfer of population and orientation in collisions of NaK molecules with argon and potassium atoms using polarization labeling (PL) and laser- induced fluorescence (LIF) spectroscopy. In the PL experiment, a circularly polarized pump laser excites a specific NaK A1Σ +(v 0=16, J 0 ) ← X1Σ +(v 00=0, J 0 ± 1) transition, creating an orientation (non-uniform MJ0 level distribution) in both levels. The linearly polarized probe laser is scanned over various 31Π(v, J 0±1) ← A1Σ +(v 0=16, J 0 ) transitions. The probe laser passes through a crossed linear polarizer before detection, and signal is recorded if the probe laser polarization has been modified by the vapor (which occurs when it comes into resonance with an oriented level). Using both spectroscopic methods, analysis of weak collisional satellite lines adjacent to these directly populated lines, as a function of argon buffer gas pressure and cell temperature, allows us to discern separately the effects collisions with argon atoms and potassium atoms have on the population and orientation of the molecule. In addition, code has been written which provides a theoretical analysis of the process, through a solution of the density matrix equations of motion for the system

SAMPERS – Erfarenheter av komplexa modeller i ett komplext utvecklingsprojekt

Swedish transportation authorities have a long tradition of developing traffic demand models. The first generation of national models was developed in the beginning of the 1980s, a second generation during the first half of 1990s. These models have also been frequently used in a large number of projects but also as a part of the regular national strategic transport investment plan. The national planning process has been a four-year cycle of revising a ten- year investment scheme. The first step in this process is to undertake an analysis to decide on a general policy (like promoting accessibility or focus on environmental protection). Here the models are used to analyse a few main alternatives, representing major differences in transportation policy and economic development (such as heavily increased petrol taxes to reduce carbondioxide emission)