Monocular Vision as a Range Sensor

One of the most important abilities for a mobile robot is detecting obstacles in order to avoid collisions. Building a map of these obstacles is the next logical step. Most robots to date have used sensors such as passive or active infrared, sonar or laser range finders to locate obstacles in their path. In contrast, this work uses a single colour camera as the only sensor, and consequently the robot must obtain range information from the camera images. We propose simple methods for determining the range to the nearest obstacle in any direction in the robot’s field of view, referred to as the Radial Obstacle Profile. The ROP can then be used to determine the amount of rotation between two successive images, which is important for constructing a 360º view of the surrounding environment as part of map construction

Directed Exploration using a Modified Distance Transform

Mobile robots operating in unknown environments need to build maps. To do so they must have an exploration algorithm to plan a path. This algorithm should guarantee that the whole of the environment, or at least some designated area, will be mapped. The path should also be optimal in some sense and not simply a "random walk" which is clearly inefficient. When multiple robots are involved, the algorithm also needs to take advantage of the fact that the robots can share the task. In this paper we discuss a modification to the well-known distance transform that satisfies these requirements

Forward stagewise regression and the monotone lasso

We consider the least angle regression and forward stagewise algorithms for solving penalized least squares regression problems. In Efron, Hastie, Johnstone & Tibshirani (2004) it is proved that the least angle regression algorithm, with a small modification, solves the lasso regression problem. Here we give an analogous result for incremental forward stagewise regression, showing that it solves a version of the lasso problem that enforces monotonicity. One consequence of this is as follows: while lasso makes optimal progress in terms of reducing the residual sum-of-squares per unit increase in $L_1$-norm of the coefficient $\beta$, forward stage-wise is optimal per unit $L_1$ arc-length traveled along the coefficient path. We also study a condition under which the coefficient paths of the lasso are monotone, and hence the different algorithms coincide. Finally, we compare the lasso and forward stagewise procedures in a simulation study involving a large number of correlated predictors.Comment: Published at http://dx.doi.org/10.1214/07-EJS004 in the Electronic Journal of Statistics (http://www.i-journals.org/ejs/) by the Institute of Mathematical Statistics (http://www.imstat.org

Serendipity Shape Function for Hybrid Fluid/Kinetic-PIC Simulations

The Sun in our solar system and stars are capable of generating enormous amounts of energy. The process by which these gaseous, celestial bodies are able to produce such large amounts of energy is called thermonuclear fusion. Fusion happens when particles collide with one another at energy levels high enough to overcome the Coulomb force and then release vast amounts of energy. Plasma, the fourth state of matter, is the natural state of stars. Plasma is an ionized gas that consists of negatively and positively charged particles. Stars, which have immense mass, can confine the plasma through their gravity to sustain the fusion process. Laboratory plasma cannot be confined by gravity. Magnetic fields can be used instead. For the past 70 years, scientists and engineers have been working on harnessing energy from magnetized thermonuclear fusion. Current research contributes to creating a device capable of supporting fusion reactions and producing a clean sustainable energy source. Sustaining a burning or ignited plasma through fusion reactions is not an easy task. These complex systems can result in many instabilities that limit plasma temperatures and densities and prevent significant thermonuclear fusion from taking place. An important piece of the physics puzzle that either stabilizes or destabilizes the plasma is the interaction of energetic particles with the bulk plasma. This is called the wave-particle interaction or energetic particle interaction with magnetohydrodynamic (MHD) modes. Another example of this would be the solar wind from the sun (energetic particles) interacting with Earth’s magnetosphere (bulk plasma). This thesis focuses on an approach to more accurately and efficiently resolve the energetic particle motions using a computer code. This thesis will also compare two very different approaches to wave-plasma interaction problem by looking at the grow-rate of an instability that has been used to benchmark several computer codes used by the magnetic fusion energy community

Master of Science

thesisAdvances in neural interfaces are putting digitization electronics closer to the patient. Since a fully implantable system is desired, there is need for a viable method for encapsulating electronics intended for implantation using a soft encapsulation method. For this thesis, several encapsulation methods were tested. Testing was split into three phases: a viability phase, a preliminary phase, and a verification phase. In the viability and preliminary phases, a method using layered Parylene C and polydimethylsiloxane was identified as having the best barrier properties. This method, along with strict attention to the cleanliness of the device, yielded very promising results. During the verification phase, devices encapsulated using this layered approach with strict attention to cleanliness performed well after going through thorough soak testing

The Internet and youth engagement: An exploration of how youth spend their time online and its relation to civic involvement

A study was conducted to investigate the relationship between Internet use and civic involvement in youth. Participants consisted of 378 youth between the ages of 16 and 25 from across Canada. Participants completed an online questionnaire consisting of a measure called the Youth Inventory of Involvement, designed to assess civic involvement in youth. Brief measures of introversion/extraversion and depression were also completed. Participants then completed questions designed to assess the amount of time they spend online in an average week, as well as for what they use the Internet. Results indicate that there may be a non-linear relationship between amount of time spent online and involvement, with individuals at the extremes in terms of very low or very high Internet use showing lower levels of involvement than more moderate users. Different types of Internet users were identified and also differed in involvement. Contrary to some previous research a link between Internet use and depression was found. This study provides important evidence that a link between Internet use and involvement in youth does in fact exist and also identifies specific types of online activities that were found to be related to both involvement and psychological well-being

Myolipoma of the Eye associate with Giant Fornix Syndrome

This is our poster submission for the research symposiu