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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.
21

A LAUNCH VEHICLE VIDEO TELEMETRY SYSTEM

Meier, Robert C. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Collecting and analyzing vehicle performance data is an essential part of the launch process. Performance data is used to determine mission success. Performance data also provides essential feedback to the launch vehicle design engineers. This feedback can be used to improve the overall vehicle design and thereby improve the probability of a successful launch. Various Telemetry products are used to gather and process critical information on board launch vehicles. Data is transmitted by RF links to fixed or mobile receiving stations. These Telemetry products are ruggedized for the extreme launch environments. This paper discusses the use of video telemetry as a means of providing launch vehicle performance data.
22

A GPS RECEIVER/TRANSMITTER UNIT FOR TRACKING LAUNCH VEHICLES

Meier, Robert C. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Launch Vehicle tracking is indispensable due to the fact that wayward vehicles must be destroyed lest they cause loss of life and/or damage to property. Launch Vehicle tracking data is also useful in assessing vehicle performance and mission success. Cincinnati Electronics (CE) has developed a Global Positioning Satellite (GPS) Receiver/Transmitter Unit (RTU), specifically for use with launch vehicles. The CE GPS RTU was flown as an experiment on the Missile Technology Demonstration (MTD) flight at White Sands Missile Range (WSMR). This paper provides an overview of CE’s GPS RTU and provides the results of CE’s GPS RTU MTD-3 flight performance.
23

Optimal trajectory reconfiguration and retargeting for the X-33 reusable launch vehicle

Shaffer, Patrick J. 09 1900 (has links)
Approved for public release; distribution is unlimited / This thesis considers the problem of generating optimal entry trajectories for a reusable launch vehicle following a control surface failure. The thesis builds upon the work of Dr. David Doman, Dr. Michael Oppenheimer and Dr. Michael Bolender of the Air Vehicles Directorate, Air Force Research Lab Dayton Ohio. The primary focus of this work is to demonstrate the feasibility of inner loop reconfiguration and outer loop trajectory retargeting and replanning for the X-33 reusable launch vehicle (RLV) following the imposition of a control surface failure. The trajectory generation model employs path constraints generated by an AFRL trim deficiency algorithm coupled with an inner loop control allocator and aerodynamic database that captures the full 6-DOF vehicle aerodynamic effects while utilizing an outer loop 3-DOF model. The resulting optimal trajectory does not violate the trim deficiency constraints and provides additional margins for trajectories flown during failure conditions. The footprints generated by the thesis show that contemporary footprint analysis for vehicles experiencing control surface failures are overly optimistic when compared to those footprints that consider vehicle aerodynamic stability and realistic landable attitudes at the threshold of the landing runway. The results of the thesis also show the performance reductions resulting from decoupling the inner and outer loop and that trajectories can be generated to the landing runway without using a region of terminal area energy management. / Commander, United States Navy
24

Role of men in programme to prevent mother-to-child transmission of HIV in Jwaneng,Botswana

Kayembe, Kazadi Nshindanyi 26 October 2006 (has links)
Masters research: Fuculty of Health Sciences / Background - The programme of prevention of mother- to-child transmission of HIV (PMTCT) was rolled out to the entire country in November 2001 after its launch in April 2000. The role of men had not been clearly defined. According to the progress report of February 2002 from PMTCT national coordination unit at family health division ministry of health, countrywide, out of 85% of pregnant women who came for antenatal care (ANC), less than 1% of these women were accompanied by their partners. However, in Jwaneng, 81% (526) of women agreed PMTCT counselling for HIV in 2003. Less than 5% (6/526) of women who agreed to be counseled, were accompanied by their men since the programme was launched in October 2001 in Jwaneng. In addition, less than 1% (2/160) of women who tested for HIV came with their partners for HIV test. Out of them, 30.5% (160/526) women agreed and tested for HIV. This testing rate was far less than the national targets of 70%. Then, 33% (52 women) tested HIV positive and 108 tested HIV negative. Of the 52 HIV positive women, 70% (36 women) joined the PMTCT programme and 4 women did not adhere. Furthermore, of 52 HIV positive women, 60% (32) of women agreed to receive AZT, adhered and chose one of the recommended methods of infant feeding. No study in Botswana had been done in a mining town to establish whether, there was a need for men to play a role in PMTCT in Jwaneng. 2 The researcher did not know whether Jwaneng pregnant women want their men or family members to come with them for PMTCT services as a motive for easy acceptance and increase of the programme uptake.
25

Towards a Trustworthy Thin Terminal for Securing Enterprise Networks

Frenn, Evan 25 April 2013 (has links)
Organizations have many employees that lack the technical knowledge to securely operate their machines. These users may open malicious email attachments/links or install unverified software such as P2P programs. These actions introduce significant risk to an organization's network since they allow attackers to exploit the trust and access given to a client machine. However, system administrators currently lack the control of client machines needed to prevent these security risks. A possible solution to address this issue lies in attestation. With respect to computer science, attestation is the ability of a machine to prove its current state. This capability can be used by client machines to remotely attest to their state, which can be used by other machines in the network when making trust decisions. Previous research in this area has focused on the use of a static root of trust (RoT), requiring the use of a chain of trust over the entire software stack. We would argue this approach is limited in feasibility, because it requires an understanding and evaluation of the all the previous states of a machine. With the use of late launch, a dynamic root of trust introduced in the Trusted Platform Module (TPM) v1.2 specification, the required chain of trust is drastically shortened, minimizing the previous states of a machine that must be evaluated. This reduced chain of trust may allow a dynamic RoT to address the limitations of a static RoT. We are implementing a client terminal service that utilizes late launch to attest to its execution. Further, the minimal functional requirements of the service facilitate strong software verification. The goal in designing this service is not to increase the security of the network, but rather to push the functionality, and therefore the security risks and responsibilities, of client machines to the network€™s servers. In doing so, we create a platform that can more easily be administered by those individuals best equipped to do so with the expectation that this will lead to better security practices. Through the use of late launch and remote attestation in our terminal service, the system administrators have a strong guarantee the clients connecting to their system are secure and can therefore focus their efforts on securing the server architecture. This effectively addresses our motivating problem as it forces user actions to occur under the control of system administrators.
26

Volare : The future of sailing

Karlsson, Rasmus, Jonson, Simon January 2016 (has links)
Sailing has gone from being an effective mode of transport to now only be a hobby. The main reason for this is that the sailboats have not had the same rate of development as other modes of transport. The main reason for this is that the sail is attached to a mast which creates a large heeling angle on the boat. Volare's solution to the problem is to use a kite sails instead of the traditional sail making so that torque is minimized considerably, which in turn means that you can reach significantly higher speeds. Volare has developed a unique solution for launch of a kite on sail boats, which contains several patented solutions. The product project team has developed stands up well against the competition in the market as it is easy to use, designed to launchas by only one person and that it takes up little space on the boat when not in use. With a less heel and higher speed are Volare on the way to creating the future way to sail.
27

Uppstart av nytt produktionsavsnitt

Johansson, Tobias, Rudin, Erik January 2012 (has links)
Detta examensarbete utfördes på DM-Motorbearbetningen vid Scania CV AB i Södertälje. DM har en plan för att öka kapaciteten i tillverkningen, detta gör att det under de närmaste åren kommer påbörjas ett antal investeringsprojekt i nya produktionsavsnitt. I dagens konkurrensutsatta marknader blir det viktigare och viktigare att vara effektiv och att ha korta ledtider i allt arbete som utförs inom industrin. I och med detta finns det stora vinster i att vid uppstart av nytt produktionsavsnitt kunna korta ned tiden som det tar till full produktionstakt. Fokus i detta arbete har legat på att identifiera möjliga orsaker till att denna tid blivit längre än vad som planerats i tidigare projekt på Scania. Historiskt när Scania har projekterat och startat nya produktionsavsnitt har det alltid tagit en viss tid innan förväntad volym och kvalitet uppnåtts efter produktionsstart. Därför behövs en process som tar hand om helheten när ett nytt produktionsavsnitt startas. En empirisk studie genomfördes där fokus låg på att intervjua tidigare projektdeltagare. Denna studie identifierade ett antal faktorer som lett till att Scania inte uppnått volym och kvalitetskrav i tid. Utifrån detta har sedan förbättringsförslag tagits fram. Flera av dessa förslag är av organisatorisk karaktär. Där produktionsledarens, operatörens och underhållsteknikerns involvering i uppstartsprojekten särskilt bör lyftas fram. Andra förbättringsförslag är tidig planering, visuell styrning och tydlig kommunikation i projekten. Utifrån de förbättringsförslag som tagits fram utformades en process, ”Uppstart av nytt produktionsavsnitt”. Denna process utformades för att ge Scania förutsättningar att komma upp i tänkt produktionstakt på ett effektivt sätt. Även en metod för att visuellt hantera denna process utvecklades. Metoden ska förenkla vid pulsmöten så projektdeltagarna vet vad som ska göras och när. Rekommendationen för fortsatt arbete är att vidareutveckla denna process och ta fram stöddokument. Genom att aktivt arbeta med att utveckla denna process och etablera ett samarbete med andra enheter inom Scania kommer DM på ett effektivare sätt kunna starta produktionsavsnitt.
28

Study of a single-stage electromagnetic launcher

Burke, Robert Adrian January 1997 (has links)
This thesis examines a single-stage barrel-less electromagnetic induction launcher, developed from an arrangement used previously for very high speed, low projectile mass accelerators. The projectile is placed on top of the launch coil, rather than inside the coil, as is more usually the case in both single and multi-stage launchers of this type. The examination is undertaken both theoretically and experimentally, with extensive experimental results being used to test the validity of the theoretical techniques used. The theoretical examination of the launcher is based on two distinct mathematical models, with results provided by the two approaches being compared. The first model uses a 2D electromagnetic finite-element approach, and does not include projectile motion or thermal effects. It is used to establish whether an analysis technique which does not take into account the projectile dynamics is a valid design tool for a single-stage launcher. The second model employs a coupled-circuit approach to take into account both projectile motion and thermal effects, and is used to obtain an accurate estimate of the overall launcher performance. With the aid of the two models the effects of varying many different launcher parameters are examined, including the size and shape of the stator coil and the size, shape and composition of the projectile. The launcher investigation could be based on a number of criteria but here it is primarily based on two; the highest average velocity over a given distance and the shortest time required to travel a given distance from the initial stationary position.
29

Legal aspects of launching and operating spacecraft

Fiallos Pazmiño, Luis Fernando January 2003 (has links)
Over the last years, the number of commercial space activities has increased tremendously. Technological developments have been the main reason in the emerging of new services that use space infrastructure. In order to provide these new space services, it is necessary to launch and operate spacecraft. / Complying with the laws and regulations of the launching and operating activities is one of the most relevant issues that prospective spacecraft operators may face in this complex industry. / This work compiles the legal sources to effectively launch and operate spacecraft destined for commercial space applications. Its goal is to identify common constraints that operators may find in the process of licensing and acquiring orbits or radio frequencies and the national/international legal principles, which govern spacecraft operations.
30

Time-domain finite elements in optimal control with application to launch-vehicle guidance

Bless, Robert R. 05 1900 (has links)
No description available.

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