Werner's Measure on Self-Avoiding Loops and Welding

Werner's conformally invariant family of measures on self-avoiding loops on Riemann surfaces is determined by a single measure $\mu_0$ on self-avoiding loops in ${\mathbb C} \setminus\{0\}$ which surround $0$. Our first major objective is to show that the measure $\mu_0$ is infinitesimally invariant with respect to conformal vector fields (essentially the Virasoro algebra of conformal field theory). This makes essential use of classical variational formulas of Duren and Schiffer, which we recast in representation theoretic terms for efficient computation. We secondly show how these formulas can be used to calculate (in principle, and sometimes explicitly) quantities (such as moments for coefficients of univalent functions) associated to the conformal welding for a self-avoiding loop. This gives an alternate proof of the uniqueness of Werner's measure. We also attempt to use these variational formulas to derive a differential equation for the (Laplace transform of) the "diagonal distribution" for the conformal welding associated to a loop; this generalizes in a suggestive way to a deformation of Werner's measure conjectured to exist by Kontsevich and Suhov (a basic inspiration for this paper)

The Effects of Hurricane Katrina on Corn, Wheat and Soybean Futures Prices and Basis

Hurricane Katrina caused considerable damage to transportation infrastructure, grain export facilities, and to some crop areas in 2005. Assuming that financial market participants considered the disruption of the grain transportation system by Katrina as having an important impact on fundamental supply and demand factors, futures and/or national basis would subsequently adjust. The objective of this research was to determine the reaction in corn, wheat, and soybean futures and basis due to Katrina using an event study methodology. One parametric (Constant mean return) and one nonparametric procedure (Corrado's rank test) were used to define whether there were statistically significant abnormal returns. During Katrina abnormal returns were larger on the wheat futures market than on the corn and soybean futures markets, which could be partially explained by the timing of the Katrina's landfall with the grain export activities. However, there were only a few statistically significant daily abnormal returns in the futures prices due to the hurricane. There was some evidence of significant cumulative abnormal returns in the corn and wheat futures markets prior to and surrounding the Katrina's landfall. In conclusion, the majority of the corn market reaction to Katrina's damage occurred in the basis and not in the futures market. For the soybean market there was weak evidence of significant reaction in both basis and futures prices. In the case of wheat, the basis was not evaluated and wheat futures prices reacted to the disruption caused by Katrina. The reaction in the corn, wheat and soybean futures prices due to Katrina could have being moderated by the presence of large stocks and large expected production levels of these grains in 2005 or simply by the fact that the damage caused by the hurricane did not affect fundamental supply and demand factors; rather, they only affected transportation logistics.Marketing,

Design of a four-point seat-belt presenter

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001.Includes bibliographical references.The ambition of this thesis was to design and prototype a seat-belt presenter of a four-point seat-belt system for the Lear Corporation. The seat-belt presenter designed is to be implemented in automobile seats in order to facilitate putting a four-point seat belt. The worked perform is the culmination of both Petr Petri and myself in our efforts to find a method to properly present a four-point seat-belt system. The design utilizes a magnet at the end of an aluminum arm that is pivoted below a person's knee on the seat. A sensor detects when a person sits down and begins a series of actions to present the seat belt. The device uses a set of four mechanical sensors to locate the position of the arm, the seat belt, and on the seat to detect when a person sits down. A control system, which utilizes logic components, then decides what direction to turn the arm in and when to stop it. The prototype that was built to simulate the seat-belt presenter appears to work well but has little details that need to worked up before a product like this enters the market. Among the most important issues to be resolved is the prototyping of the second arm on the presenter, the mounting of the motor and sensors onto the mount, use of the appropriate sensors, and to address the problem of the electrical components overheating.by Miguel Angel Chavez.S.B

Limiting Distributions of Sums with Random Spectral Weights

This paper studies the asymptotic properties of weighted sums of the form $Z_n=\sum_{i=1}^n a_i X_i$, in which $X_1, X_2, \ldots, X_n$ are i.i.d.~random variables and $a_1, a_2, \ldots, a_n$ correspond to either eigenvalues or singular values in the classic Erd\H{o}s-R\'enyi-Gilbert model. In particular, we prove central limit-type theorems for the sequences $n^{-1}Z_n$ with varying conditions imposed on $X_1, X_2, \ldots, X_n$

Handover analysis over mobile WiMAX technology.

As new mobile devices and mobile applications continue to growth, so does the data traffic demand for broadband services access and the user needs toward mobility, thereby, wireless application became today the fastest solution and lowest cost implementation unlike traditional wired deployment such as optical fibers and digital lines. WiMAX technology satisfies this gap through its high network performance over the air interface and high data rates based on the IEEE 802.16-2004 standards, this original specification does not support mobility. Therefore, the IEEE introduces a new standard that enables mobility profiles under 802.16e-2005, from which three different types of handovers process are introduced as hard handover (HHO), macro diversity handover (MDHO) and fast base station switching (FBSS) handover. The objective of this master thesis is to analyze how the handover process affects network performance. The analysis propose three scenarios, built over OPNET simulator to measure the most critical wireless parameter and performance indicator such as throughput, handover success rate, packet drop, delay and network usage.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Discrete Approximation of Coloring the Plane

 This work is inspired by the open problem The Chromatic Number of The Plane. We approximate the plane by only considering points with coordinates (p/n, q/n), where p and q are integers, and n is a fixed positive integer. To prevent triviality, we add the restriction that two points are adjacent if and only if their distance is between 1-ε and 1+ε for a non-negative ε. Adjacent points have to be colored differently. Our goal is to find the smallest ε for each n that will force us to use five colors

Características de la producción de objetos de aprendizaje por autores no especialistas en TIC

Con el objetivo de caracterizar el proceso de producción de objetos de aprendizaje por autores no especialistas en tecnologías de la información y la comunicación se realizó una encuesta entre los docentes del Centro Universitario de la Universidad Autónoma del Estado de México, campus Texcoco. Este artículo presenta los resultados de la encuesta y los analiza

Propuesta de soluciones tecnicas para contrarrestar los efectos del fenomeno el niño en el canton tosagua, provincia de Manabí

La ciudad de Tosagua, en la Provincia de Manabí, fue uno de los lugares más afectados por los efectos del Fenómeno El Niño, el objetivo principal de la presente tesis fue encontrar las razones para los daños ocurridos así como plantear las soluciones y recomendaciones a fin de prevenir los efectos de nuevos Fenómenos El Niño. Una vez realizados los estudios se pudo comprobar que las principales causas de los daños que se provocaron fueron los siguientes: Ablandamiento de los terrenos (principalmente por sus características de ser arcillas expansivas); Deficiencias en el drenaje; Deficiencias en el diseño y construcción de los pavimentos de vías; Deficiencias en la construcción de las obras básicas; Falta de planificación en la ejecución de obras; La inexistencia de alcantarillado de agua servidas. Siendo el principal problema el gran poder de expansión (hinchamiento al entrar en contacto con el agua), el principal objetivo del trabajo fue encontrar un tratamiento adecuado para controlar dicha expansión, fue así como luego de varias pruebas se logró encontrar un procedimiento económicamente rentable que permite controlar casi en un 90% lo cual permitirá que las obras a construirse puedan soportar futuras presencias de Fenómenos El Niño