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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Tailorable Remote Unmanned Combat Craft

Jacobi, Loren, Campbell, Rick, Chau, Chee Nam, Ong, Chin Chuan, Tan, Szu Hau, Cher, Hock Hin, Alexander, Cory, Edwards, Christien, Diukman, Anner, Ding, Sze Yi, Hagstette, Matthew, Kwek, Howe Leng, Bush, Adam, Meeks, Matt, Tham, Kine Yin, Ng, Mei Ling, Yeo, Ing Kang, Loke, Yew Kok 06 1900 (has links)
Approved for public release; distribution is unlimited. / U.S. military and civilian vessels are critically vulnerable to asymmetric threats in littoral environments. Common asymmetric weapons such as Anti-Ship Cruise Missiles (ASCM), Low Slow Flying (LSF) aircraft and Fast Attack Craft (FAC) / Fast Inshore Attack Craft (FIAC) threaten U.S. strategic goals and can produce unacceptable losses of men and material. The SEA-18B team presents an operational concept for a family of Unmanned Surface Vessels USV) capable of defending ships from asymmetric swarm attacks. This USV, the Tailorable Remote Unmanned Combat Craft (TRUCC), can operate in concert with the next generation of capital surface vessels to combat this critical threat with maximum efficiency. Critical performance criteria of the TRUCC family were determined through agent-based simulation of a Straits of Hormuz Design Reference Mission. Additional models addressed ship synthesis and operational availability. A Technology and Capability Roadmap outlines areas of interest for investment and development of the next-generation USV. Interim technology and capability milestones in the Roadmap facilitate incremental USV operational capabilities for missions such as logistics, decoy operations and Mine Warfare. The TRUCC operational concept fills a critical vulnerability gap. Its employment will reduce combat risk to our most valuable maritime assets: our ships and our Sailors.
2

Site-specific Facilitation or Inhibition of Dopamine-reward by Viral Transfection of M5 Muscarinic Receptors in the Tegmentum of M5 Knockout Mice

Wasserman, David 28 July 2010 (has links)
Knockdown of the M5 acetylcholine muscarinic receptor in the ventral tegmental area (VTA) reduces brain-stimulation reward sensitivity in rats. Knockout (KO) of the M5 receptor in mice reduces morphine-induced dopamine efflux, locomotion, conditionedplace- preference, and mating-induced 30-110 kHz ultrasonic vocalizations (USVs). The GFP-labeled M5 receptor gene was transfected using a Herpes simplex virus either into the VTA or 0.2-0.7 mm posterior in the medial tegmentum (MT) of male M5 KO mice. HSV-M5-GFP transfection in VTA fully restored mating-induced USVs and augmented morphine-induced locomotion and stereotypy consistent with activation of DA neurons by M5 receptors. HSV-M5-GFP transfection sites in the MT inhibited USVs and morphine-induced locomotion presumably through inhibition of DA neurons. Putative transfection of M5 in GABA neurons of the rostromedial tegmental nucleus (RMTg) or 5HT neurons of the median raphe (mR) may explain this inhibition. Therefore, HSV-M5- GFP transfection in the VTA enhances DA-mediated behaviours while MT transfections inhibits these behaviours.
3

Site-specific Facilitation or Inhibition of Dopamine-reward by Viral Transfection of M5 Muscarinic Receptors in the Tegmentum of M5 Knockout Mice

Wasserman, David 28 July 2010 (has links)
Knockdown of the M5 acetylcholine muscarinic receptor in the ventral tegmental area (VTA) reduces brain-stimulation reward sensitivity in rats. Knockout (KO) of the M5 receptor in mice reduces morphine-induced dopamine efflux, locomotion, conditionedplace- preference, and mating-induced 30-110 kHz ultrasonic vocalizations (USVs). The GFP-labeled M5 receptor gene was transfected using a Herpes simplex virus either into the VTA or 0.2-0.7 mm posterior in the medial tegmentum (MT) of male M5 KO mice. HSV-M5-GFP transfection in VTA fully restored mating-induced USVs and augmented morphine-induced locomotion and stereotypy consistent with activation of DA neurons by M5 receptors. HSV-M5-GFP transfection sites in the MT inhibited USVs and morphine-induced locomotion presumably through inhibition of DA neurons. Putative transfection of M5 in GABA neurons of the rostromedial tegmental nucleus (RMTg) or 5HT neurons of the median raphe (mR) may explain this inhibition. Therefore, HSV-M5- GFP transfection in the VTA enhances DA-mediated behaviours while MT transfections inhibits these behaviours.
4

Development and Systems Integration of Small Hydrofoiling Robot for Mapping and Sensing / Utveckling och systemintegration av liten bärplansrobot för kartläggning och avkänning

Lopperi, Tommy, Söderberg, Henrik January 2022 (has links)
Unmanned surface vehicles (USVs) are vehicles of various levels of autonomy which can be made for a large variety of purposes, for instance ferriage and surveying. USV shave technically been around for about 80 years, however, it is only within fairly recent years developments in miniaturization of components and computers have allowed for the construction of USVs of a small size. The primary benefit of USVs is that they can perform otherwise costly and tedious tasks originally done by manned vehicles. They can also run on electric batteries; thus limiting the effect on the environment compared to the fossil fuels used in traditional vehicles. In this project, performed at the Swedish Maritime Robotics Center at KTH Stockholm, a small USV meant to perform depth measurements of waterways was developed. It can be steered via remote control and has the hardware required to navigate autonomously. This report goes through the multiple steps the project group undertook to develop the USV. The project included studying of previous works, selection and ordering of components, creating a schematic, developing the programming, and testing. 11 components were installed while several planned ones were not included due to time constraints. Testing of the remote control and GNSS logging was successful. / Obemannade ytfarkoster (engelska USV) är fordon med olika nivåer av autonomi som kan tillverkas för en mängd olika ändamål, till exempel för färjor och hydrografi. USV har tekniskt sett funnits i cirka 80 år, men det är först inom de relativt senaste åren utvecklingen inom miniatyrisering av komponenter och datorer har möjliggjort konstruktion av USV:s av en liten storlek. Den främsta fördelen med USV är att de kan utföra annars kostsamma och mödosamma uppgifter som ursprungligen utfördes av bemannade fordon. De kan också köras på elektriska batterier; vilket begränsar effekten på miljön jämfört med de fossila bränslen som används i traditionella fordon. I detta projekt, utfört på Swedish Maritime Robotics Center vid KTH Stockholm, utvecklades en liten USV för att utföra djupmätningar av vattendrag. Den kan styras via fjärrkontroll och har den hårdvara som krävs för att navigera självständigt. Denna rapport går igenom de steg som projektgruppen tog för att utveckla USV:n. I projektet ingick att studera tidigare arbeten, välja och beställa komponenter, skapa tekniska diagram, utveckla programmeringen och testning. 11 komponenter installerades medan flera planerade inte ingick på grund av tidsbrist. Testning av fjärrkontrollen och GNSS-loggningen var lyckade.
5

Mission tasking of unmanned vehicles

Johnson, Jada E. 06 1900 (has links)
Approved for public release, distribution is unlimited / Unmanned vehicles (UVs) are expected to be an integral part of the U.S. Navy's expeditionary and carrier strike groups and are quickly being integrated into maritime operations. Command and control issues must be resolved, however, in order to utilize unmanned systems as intelligence, surveillance, and reconnaissance assets. The purpose of this research was to assess the current doctrine of mission tasking with respect to tactical unmanned vehicles (UVs) and determine a method for effectively tasking these systems. The problem was analyzed by applying the factors of METT-T: mission, enemy, terrain and weather, troops and support available, and time available to UV-enabled maritime missions. The analysis identified specific implications for unmanned vehicles and emphasized important considerations for tasking and allocating UVs. METT-T analyses generally result in courses of action, however, tasking is a command and control issue, and therefore, four organizational structures emerge for tasking UVs A significant finding of this study is that the current doctrinal framework of the composite warfare commander's concept can support tasking unmanned vehicles, but requires revision to effectively address UV allocation issues. / Ensign, United States Navy
6

Control and Autonomy of a Water Quality Measuring Unmanned Surface Vehicle (USV) : Catfish project - Control and Autonomy

Hårding, Vidar January 2021 (has links)
This report is about the implementation of autonomy and control on a water quality measuring unmanned surface vehicle. The project was termed Catfish and involved five teams focusing on different aspects of the initial goal to create an autonomous three-part system; a surface drone, a submerged drone and flying drone. In this iteration of the Catfish project the focus laid on creating the surface drone and submerged drone as the Catfish project will improve over generations of thesis projects. The author of the report was in the Control and Autonomy team and had been tasked with giving the surface drone the autonomy needed to make this project viable. Existing advances made in autonomy was adopted and tested. With the help of estimation algorithms, and sensor fusion, a flight controller navigates the surface drone between a set of GPS waypoints. It is also able to counteract the external forces wind, waves and stream to keep its position. To reach this autonomy four test phases were conducted on a pre-prototype with progressively increased difficult autonomy starting with manual control and ending in advanced autonomy. When the advanced missions were executed the speed and accuracy of two different thruster configurations were examined and the best performing out of the two was implemented on the final prototype the other teams had designed. The project ended with a fully autonomous system that was able to execute all the navigational maneuvers required to operate autonomous water quality measuring missions. / Den här rapporten handlar om implementationen av autonomi och kontroll på en vattenkvalitetsmätande vattenburen drönare. Projektet fick namnet Catfish och blev indelat i fem teams som fokuserade på olika aspekter av ett 3-delsystem; en vattenburen, en undervattens och en flygande drönare. I denna iteration av Catfish projektet fokuserade medlemmarna på att utveckla den vattenburna och undervattens drönaren då projektet kommer fortsätta utvecklas under kommande generationer av Catfish projektrapporter. Författaren av den här rapporten ingick i ett team som hette "Control and Autonomy" och hade i uppgift att installera en autonom intelligens till den vattenburna drönaren för att göra Catfish prototypen användbar. Befintliga framsteg inom forskningsområdet blev granskade och testade. Genom att använda uppskattningsalgoritmer och "sensor fusion" lyckades en "flight controller" navigera drönaren mellan GPS waypoints och även behålla sin position genom att motverka krafterna från vind, vågor och strömmar. För att uppnå denna nivå av autonomi utför en förprototyp fyra test faser av ökad autonomisk svårhetsgrad. Under uppdraget blev hastigheten och precisionen av två olika motoruppsättningar undersöka och den som presterade bäst blev implementerad på den slutgiltig designen som de andra teamen hade utvecklat. Projektet avslutades med att ett fullt autonomt system blev utvecklat som var kapabel till att utföra alla navigationsmanövrar nödvändiga för att genomföra autonoma vattenkvalitetsmätningsuppdrag.
7

The Effect of Time of Expsoure to Polychlorinated Biphenyl (PCB) on Thyroid Status and Ultrasonic Vocalizations in Sprague Dawley Rats

King, Samantha L. 29 July 2013 (has links)
No description available.
8

Autonomous and Cooperative Landings Using Model Predictive Control

Persson, Linnea January 2019 (has links)
Cooperation is increasingly being applied in the control of interconnected multi-agent systems, and it introduces many benefits. In particular, cooperation can improve the efficiency of many types of missions, and adds flexibility and robustness against external disturbances or unknown obstacles. This thesis investigates cooperative maneuvers for aerial vehicles autonomously landing on moving platforms, and how to safely and robustly perform such landings on a real system subject to a variety of disturbances and physical and computational constraints. Two specific examples are considered: the landing of a fixed-wing drone on top of a moving ground carriage; and the landing of a quadcopter on a boat. The maneuvers are executed in a cooperative manner where both vehicles are allowed to take actions to reach their common objective while avoiding safety based spatial constraints. Applications of such systems can be found in, for example, autonomous deliveries, emergency landings, and search and rescue missions. Particular challenges of cooperative landing maneuvers include the heterogeneous and nonlinear dynamics, the coupled control, the sensitivity to disturbances, and the safety criticality of performing a high-velocity landing maneuver. The thesis suggests the design of a cooperative control algorithm for performing autonomous and cooperative landings. The algorithm is based on model predictive control, an optimization-based method where at every sampling instant a finite-horizon optimal control problem is solved. The advantages of applying this control method in this setting arise from its ability to include explicit dynamic equations, constraints, and disturbances directly in the computation of the control inputs. It is shown how the resulting optimization problem of the autonomous landing controller can be decoupled into a horizontal and a vertical sub-problem, a finding which significantly increases the efficiency of the algorithm. The algorithm is derived for two different autonomous landing systems, which are subsequently implemented in realistic simulations and on a drone for real-world flight tests. The results demonstrate both that the controller is practically implementable on real systems with computational limitations, and that the suggested controller can successfully be used to perform the cooperative landing under the influence of external disturbances and under the constraint of various safety requirements. / Samarbete tillämpas i allt högre utsträckning vid reglering av sammankopplade multiagentsystem, vilket medför både ökad robusthet och flexibilitet mot yttre störningar, samt att många typer av uppgifter kan utföras mer effektivt. Denna licentiatavhandling behandlar kooperativa och autonoma landningar av drönare på mobila landingsplatformar, och undersöker hur sådana landningar kan implementeras på ett verkligt system som påverkas av externa störningar och som samtidigt arbetar under fysiska och beräkningsmässiga begränsningar. Två exempel betraktas särskilt: först landingen av ett autonomt flygplan på en bil, därefter landning av en quadcopter på en båt. Landningarna utförs kooperativt, vilket innebär att båda fordonen har möjlighet att påverka systemet för att fullborda landningen. Denna typ av system har applikationer bland annat inom autonoma leveranser, nödlandningar, samt inom eftersöknings- och räddningsuppdrag. Forskningen motiveras av ett behov av effektiva och säkra autonoma landingsmanövrar, för fordon med heterogen och komplex dynamik som samtidigt måste uppfylla en mängd säkerhetsvillkor. I avhandlingen härleds  kooperativa regleralgoritmer för landningsmanövern. Reglermetoden som appliceras är modell-prediktiv reglerteknik, en optimeringsbaserad metod under vilken ett optimalt reglerproblem med ändlig horisont löses  varje samplingsperiod. Denna metod tillför här fördelar såsom explicit hantering av systemdynamik, och direkt inkludering av störningshantering och bivillkor vid beräkning av insignaler. På så sätt kan vi direkt i optimeringslösaren hantera säkerhetsvillkor och externa störningar. Det visas även hur lösningstiden för optimeringen kan effektiviseras genom att separera den horisontella och den vertikala dynamiken till två subproblem som löses sekvensiellt. Algoritmen implementeras därefter för två olika landingssystem, för att därefter tillämpas och utvärderas i realistiska simuleringsmiljöer med olika typer av störningar, samt med flygtester på en verklig plattform. Resultaten visar dels att reglermetoden ger önskade resultat med avseende både på störningshantering och uppfyllande av bivillkor från säkerhetskrav, och dels att algoritmen är praktiskt implementerbar även på system med begränsad beräkningskraft. / <p>QC 20190315</p>
9

Fabrication and Automation of a Power-Conserving USV in Moving Water

Joseph Peter Wichlinski (11015460) 23 July 2021 (has links)
Water pollution in drinking water is a major concern in rural areas that depend on local surface and ground water supplies. The Amazon river, for example, has800 thousand rural inhabitants, many of whom do not have access to treated water. Reaching the Amazon River to collect these water samples is already a complicated task. With constantly changing floodplains, and therefore water quality, the ability to collect water samples remotely and autonomously can help rural areas monitor their drinking water. There have been several studies investigating different unmanned surface vehicle (USV)prototypes and data collection methods. However, none have specifically made a compact USV to maneuver in rivers, while aiming to conserve energy to drive longer distances. This paper describes an in-depth design, fabrication, and automation process for a USV to drive in the Wabash River. The USV monitors its own location, speed, and battery voltage for power consumption analysis. As proof of concept, the USV measures water depth during field studies performed in Lake Harner, Indiana and the Wabash River. These field studies yield affirming results for the controls logic and power conservation of the designed USV.<br>
10

Determination of a Two-Week `Window&#x2019; for PCB Influence on Ultrasonic Vocalization and Other Behavioral Measures in Young Sprague-Dawley Rats

Baldwin, Jeffrey W., Jr. 09 July 2014 (has links)
No description available.

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