Design, construction, and operation of an unmanned underwater vehicle

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2009.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (leaf [62]).The practical usage of unmanned underwater vehicles (UUVs) is limited by vehicle and operation cost, difficulty in accurate navigation, and communication between the vehicle and operator. The "Rex 2" UUV employs a system design where a submersible is connected to a float at the water's surface by means of a tether. By maintaining a surface expression, high-bandwidth radio communication to the operator becomes possible, and GPS may be used for accurate navigation. This arrangement allows the freedom of movement characteristic of untethered autonomous underwater vehicles (AUVs), while maintaining the live operator control and communication found with tethered remotely operated vehicles (ROVs). Expanding on the design and field experiences with the MIT AUV Lab's first Reef Explorer UUV, Rex 2 was designed to be inexpensive, easy to deploy, adaptable to various payloads, and simple to use. Rex 2 was designed, built, and operated in a number of ocean field tests, validating the utility of the vehicle and system concept.by Dylan Owens.S.M

Exploring the relationship between team characteristics and mental health symptoms amongst student athletes

Depression and anxiety are disabling conditions that are particularly prevalent amongst young adults (Wolanin, Hong, Marks, Panchoo, & Gross, 2016). Student athletes must cope with extensive time demands that go beyond those of ordinary young adults, consequently putting them at increased risk to experiencing mental health issues. Numerous factors may influence an athlete’s well being, such as gender, injury, and type of sport. This study tests these various factors but also extends previous literature by analyzing the effects of team dynamics on student athlete mental health. An anonymous multi-part questionnaire was sent out to all JMU athletes in the Fall of 2017. Chi square statistical tests were used to determine whether there was a mathematical association between team characteristics and the presence or absence of mental health symptoms. There was a significant correlation between ‘pressure’ and anxiety (X2 = 13.403, p = .009). In addition, ‘inability to trust teammates’ and ‘not sharing goals of personal improvement’ also contributed to increased levels of anxiety. There was a significant correlation between serious injuries and depression (X2 = 4.325, p = .038). Lack of time for social life and inability to effectively manage conflicts within the team both contributed to increased levels of depression as well. Fortunately, the data showed that JMU’s student athletes had higher mental health scores than American college students as a whole, according to prior research, and they do feel as though the resources available to them are adequate

On Dealing with Life

Sometimes, life isn\u27t about getting what you want; it\u27s about surviving what you don\u27t want

Design and Performance of Odyssey IV: A Deep Ocean Hover-Capable AUV

The Odyssey IV class AUV was designed to fill the evolving needs of research and industry for a deep rated (6000 meter) vehicle, which is capable of both efficient cruising and precise hovering. This AUV is powerful enough to reject currents typical in the open ocean environment and yet small enough to be deployed from a small fishing boat. The thruster layout, two vectored side thrusters and two fixed cross-body thrusters, allow for 4-DOF control, which gives this vehicle precision and flexibility not possible in previous Odyssey class AUVs. An adaptable payload area allows the mounting of sensors, actuators, or other hardware suitable to a particular mission. The dynamic control layer of our behavior-based MOOS software was completely redesigned to take advantage of the capabilities of this vehicle. This is also the first platform to utilize new graphical controls and database-driven logging which increase operator efficiency and make the vehicle safer to operate. Odyssey IV's intended uses include survey and inspection of cold water corals, fisheries, archaeological sites, and subsea infrastructure. It will also serve as a research platform for computer vision-based servoing and acoustic supervisory control. This paper will document the design considerations and implementation of the Odyssey IV, as well as report on a series of field tests culminating in its first scientific deployment at Georges Bank, observing and mapping the invasive tunicate Didemnum.United States. National Oceanic and Atmospheric Administration (Grant NA16RG2255); United States. National Oceanic and Atmospheric Administration (Grant NA06AOR4170019

Parallel shifts of visual sensitivity and body coloration in replicate populations of extremophile fish

Visual sensitivity and body pigmentation are often shaped by both natural selection from the environment and sexual selection from mate choice. One way of quantifying the impact of the environment is by measuring how traits have changed after colonization of a novel habitat. To do this, we studied Poecilia mexicana populations that have repeatedly adapted to extreme sulphidic (H2 S-containing) environments. We measured visual sensitivity using opsin gene expression, as well as body pigmentation, for populations in four independent drainages. Both visual sensitivity and body pigmentation showed significant parallel shifts towards greater medium-wavelength sensitivity and reflectance in sulphidic populations. Altogether we found that sulphidic habitats select for differences in visual sensitivity and pigmentation. Shifts between habitats may be due to both differences in the water's spectral properties and correlated ecological changes

Disk or Companion: Characterizing Excess Infrared Flux in Seven White Dwarf Systems with Near-Infrared Spectroscopy

Excess infrared flux from white dwarf stars is likely to arise from a dusty debris disk or a cool companion. In this work, we present near-infrared spectroscopic observations with Keck/MOSFIRE, Gemini/GNIRS, and Gemini/Flamingos-2 of seven white dwarfs with infrared excesses identified in previous studies. We confirmed the presence of dust disks around four white dwarfs (Gaia J0611-6931, Gaia J0006+2858, Gaia J2100+2122, and WD 0145+234) as well as two new white dwarf brown dwarf pairs (Gaia J0052+4505 and Gaia J0603+4518). In three of the dust disk systems, we detected for the first time near-infrared metal emissions (Mg I, Fe I, and Si I) from a gaseous component of the disk. We developed a new Markov Chain Monte Carlo framework to constrain the geometric properties of each dust disk. In three systems, the dust disk and the gas disk appear to coincide spatially. For the two brown dwarf white dwarf pairs, we identified broad molecular absorption features typically seen in L dwarfs. The origin of the infrared excess around Gaia J0723+6301 remains a mystery. Our study underlines how near-infrared spectroscopy can be used to determine sources of infrared excess around white dwarfs, which has now been detected in hundreds of systems photometrically.Comment: 23 pages, 10 figures, 5 tables, AJ, in pres

Concert recording 2017-04-12b

[Track 1]. Angel Falls / Lewis Songer -- [Track 2]. Grand Canyon Octet. Andante appassionato [Track 3]. Lento-allegro molto / Eric Ewazen -- [Track 4]. Quipperies / Lowell Shaw -- [Track 5]. Birdland / Josef Zawinul arranged by Kummerlander

Concert recording 2017-11-15

[Track 1]. Fanfare for barcs / Kerry Turner -- [Track 2]. Three for five / James Naigus -- [Track 3]. Big sky country / Daniel Baldwin

The Vehicle, Spring 1996

Vol. 37, No. 2 Table of Contents Poetry AnyoneKeith Owenspage 2 Of Words and WidgetsJ. Dylan McNeillpage 3 HouseplantsPeter W. Katespage 4 IcarusJeff Vande Zandepage 5 UntitledPatrick F. Kellypage 7 CommuteWhitty Whitesellpage 8 During Graduate SchoolJeff Vande Zandepage 9 NeuteredJason S. Loguepage 10 Bitter WritingJ. Dylan McNeillpage 11 Song to Unknown SoldiersM. Olatoye Bayieupage 12 SoftAmy Haynespage 13 Mother\u27s Crossword PuzzlesMatthew J. Nelsonpage 14 Prose Cold ShowerMatt Parkspage 17 Your Title HereKeith Owenspage 20 Biographies Authorspage 27https://thekeep.eiu.edu/vehicle/1067/thumbnail.jp

Emergent Imaging and Geospatial Technologies for Soil Investigations

Soil survey investigations and inventories form the scientific basis for a wide spectrum of agronomic and environmental management programs. Soil data and information help formulate resource conservation policies of federal, state, and local governments that seek to sustain our agricultural production system while enhancing environmental quality on both public and private lands. The dual challenges of increasing agricultural production and ensuring environmental integrity require electronically available soil inventory data with both spatial and attribute quality. Meeting this societal need in part depends on development and evaluation of new methods for updating and maintaining soil inventories for sophisticated applications, and implementing an effective framework to conceptualize and communicate tacit knowledge from soil scientists to numerous stakeholders