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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.
71

Nanospectroscopie infrarouge avancée : développements instrumentaux et applications / Advanced infrared nanospectroscopy : instrumental developments and applications

Mathurin, Jérémie, 27 June 2019 (has links)
Depuis une dizaine d’années, les technologies de champ proche appliquées à la spectroscopie infrarouge ont connu de rapides progrès permettant d’atteindre maintenant l’échelle du nanomètre. Dans le cadre de ma thèse, l’une de ces techniques, appelées AFM-IR et qui consiste à un couplage entre la microscopie à force atomique (AFM) et un laser accordable dans le domaine de l’infrarouge, va être présenté plus en détail.Le but de ma thèse va être de présenter les différents développements qui ont eu lieu dans le domaine de cette technique, comme l’AFM-IR en résonance forcée, l’AFM-IR en mode tapping ou les débuts du développement de l’AFM-IR avec des sources spectralement continues. Ces développements majeurs ont eu pour conséquence de populariser la technique et de voir une rapide augmentation du nombre d’utilisateurs. Cependant l’AFM-IR reste une technique récente et non triviale à maitriser, car elle demande à la fois des connaissances en AFM, mais aussi en spectroscopie infrarouge.Les dernières avancées technologiques ont permis de s’approcher de la résolution nanométrique. Les conséquences sont multiples et notamment cela permet d’ouvrir la technique à de nouveaux champs d’applications. Or qui dit nouveaux domaines dit nouvelles problématiques, mais surtout nouveaux challenges expérimentaux. Il est donc important d’identifier les verrous technologiques et limitations associés à ces développements pour garder un esprit critique sur ce qui peut être ou non obtenu en AFM-IR et éviter des erreurs d’interprétation et/ou d’analyse qui pourraient avoir des conséquences néfastes dans les champs d’applications étudiés. / For 10 years, near-field technologies applied to infrared spectroscopy have reached milestones and now are able to make analysis at nanoscale. In my PhD thesis, I will focus on one of these techniques: the so-called AFM-IR technique which combined an atomic force microscope (AFM) with a pulse laser tunable in the infrared spectral range.The main goal of my PhD thesis will be to present the last developments which appears for this technique such as resonance enhanced AFM-IR, tapping mode AFM-IR or the first measurements of AFM-IR with broadband sources. These developments are major in the field of the technique and have led to high increase of the numbers of users. However, AFM-IR remains a recent and complicated technique where user has to master in the same time atomic force microscopy and infrared spectroscopy.The last technological developments allow measurements at the nanoscale. This has multiple consequences, especially it opens new applications fields. It also generates new problematic and new experimental challenges. As a consequence, it is necessary to understand new technological limitations created by these new developments in order to stay critical of the results obtained with an AFM-IR measurement and avoid analysis and interpretation errors which can have bad consequences on the different fields of study.
72

The development of a simple stereotactic device for neurosurgical applications

Van Geems, Barbara Anne 03 May 2017 (has links)
No description available.
73

A plethysmographic device for determining human body volume and body density

Cronjé, Thomas Frederick January 1992 (has links)
The measurement of total body volume (V) (excluding lung volume) together with total body mass (m) is required in order to determine body density (d = m/V). From this, and using certain simplifying assumptions, it is possible to derive body composition in terms of fat mass (FM) and fat free mass (FFM) for the two-compartment model. The standard method for determining body volume (and hence body composition) is the densitometric (underwater weighing) technique based on Archimedes' principle. Three variables, notably residual lung volume (RV), total body mass (m) and submerged body mass are measured. RV is normally determined using a gas dilution technique while total body mass is simply measured using an accurate weighing scale. The submerged body mass is measured while the subject is totally submerged in a tank of water. This method, although relatively accurate, requires substantial apparatus and is time consuming. An alternative method, based on a polytropic thermodynamic process, is described for body volume measurement and thereby for body composition assessment. Previous use of this method by Taylor, et al. (1985) and Gundlach and Visscher (1986) were successful, but complex in terms of operating system. The described system comprises of a Perspex, sealed chamber. A cycling piston communicates with the chamber and imposes a minute sinusoidal pressure variation which is then measured. With a subject situated inside the chamber an increased pressure variation, caused by the decreased chamber volume, is then measured and processed to yield the displaced, or body volume. Subject comfort, above all, is greatly enhanced, in comparison to the underwater weighing method. A substantial advantage of the method appears to be that RV need no longer be measured. Variables such as a rise of temperature and humidity caused by the subject, as well as pressure variations due to respiration, were expected and found. These were analyzed both theoretically and experimentally and where necessary the data were modified to account for these variables using a personal computer. Calibration and preliminary validation of the instrument has been carried out using underwater weighing, bioimpedance and skinfold analyses and the error of measurement assessed. It appears that the described plethysmographic method is capable of measuring body volume and thus compares favourably to the underwater weighing method. Even though other groups have succeeded in employing similar principles, a substantially simpler mechanism has been used here.
74

METADATA FOR RANGE TELEMETRY

Grace, Thomas, Fink, Clay 10 1900 (has links)
ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / CTEIP has launched the integrated Network Enhanced Telemetry (iNET) project to foster advances in networking and telemetry technology to meet emerging needs of major test programs. This paper describes an approach for providing a unified means of describing telemetry systems. It will describe the motivation and framework for a metadata standard for specifying the components of an instrumented test article, its data and the flow of data through a telemetry system. The paper will also describe how this metadata standard can provide the means for describing different transmission formats for a common test article. The result of the task described by this paper will lead to a standard or set of standards that will optimize the use of commercial technology and tools.
75

XML Data Modeling for Network-Based Telemetry Systems

Price, Jeremy C., Moore, Michael S., Malatesta, Bill A. 10 1900 (has links)
ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / Network-based telemetry systems are often made up of many components from multiple vendors. The complexity involved in coordinating the design, integration, configuration, and operation of these systems has required instrumentation engineers to become experts in the tools and hardware from various vendors. Interoperation between the various tools and systems is very limited. One approach toward a more efficient method of managing these systems is to define a common language for describing the goals of the test, the measurements to be acquired, and the equipment that is available to compose a system. Through an open working group process, the iNET program is defining an eXtensible Markup Language (XML)-based language for describing instrumentation and telemetry systems. The language is designed with multiple aspects that allow filtered views into the instrumentation system, making the creation of the various parts of the documents more straight-forward and understandable to the type of user providing the information. This paper will describe the iNET metadata project, the model-driven approach that is being pursued, and the current state of the iNET metadata language.
76

A Comparison of Various Video Compression Methods for Use in Instrumentation Systems

Rieger, James L., Gattis, Sherri L. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Various forms of 'lossy' and 'lossless' encoding have been implemented or proposed to allow compression of still and motion picture images, with varying degrees of success which in turn depend on how success is defined. Proponents of various systems claim 'compression ratios' which by their nature defy comparison of one system with another and suggest there actually may be something like a free lunch. This paper compares various compression methods as well as the implications involved in using them and what happens when different systems encounter the problems associated with the uses of the restored picture.
77

ADVANCED AIRBORNE TEST INSTRUMENTATION SYSTEM (AATIS) PROGRAM SYSTEM OVERVIEW

Chang, Dah W. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Advanced Airborne Test Instrumentation System (AATIS), one of the major instrumentation systems in use today by the Department of Defense (DoD), was developed in the late 1980's to improve and modernize its predecessor - the Airborne Test Instrumentation System (ATIS). Use of AATIS, by not only the Air Force but the Navy and Army, has improved instrumentation commonality and interoperability across multiple test programs. AATIS, developed by the same manufacturer as the DoD Common Airborne Instrumentation System (CAIS), has a common bus structure - enabling cross utilization of many components which will ease transition from one system to another. The objective of this paper is to provide an overview on the Advanced ATIS System and its logistics support concept. For system description, an overview is presented on the airborne system and related ground support equipment. A brief description is given on the three levels of maintenance being used or planned for by the using activities. Finally, a projection is presented on the utilization of this system for the next 3 years.
78

HIGH SPEED AVIONICS DATA INSTRUMENTATION SYSTEM (HADIS)

Black, James A. 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / SAIC, under contract with the Air Force Wright Laboratory, has developed and demonstrated a prototype High Speed Avionics Data Instrumentation System (HADIS). The HADIS system is designed to operate in both the laboratory and in an airborne environment. This paper briefly describes the features of the system including its ability to collect and record data at up to 13.25 MBytes per second, its ability to provide real-time processing of the data, and its ability to rapidly reconfigure its interfaces based on field programmable gate arrays. The paper discusses the need for multiple data paths within the system to allow parallel operations to take place, the need for dedicated access to the recorder subsystem, and methods for allowing selective recording based on the information content of the data. The effort was sponsored by the Test Facility Working Group to provide a common data collection system for Air Force logistics and test and evaluation facilities. The design is owned by the government and may be cost-effectively used by any government agency.
79

HARDENED SUBMINIATURE TELEMETRY AND SENSOR SYSTEM

Faulstich, Raymond J., Burke, Lawrence W. Jr, D’Amico, William P. 10 1900 (has links)
International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / The Army development and test community must demonstrate the functionality and reliability of gun-launched projectiles and munitions systems, especially newer smart munitions. The best method to satisfy this requirement is to combine existing optical and tracking systems data with internal data measured with on-board instrumentation (i.e. spin, pitch, and yaw measurements for standard items and terminal sensor, signal processor, and guidance/navigation system monitoring for smart munitions). Acquisition of internal data is usually limited by available space, harsh launch environments, and high associated costs. A technology development and demonstration effort is underway to provide a new generation of products for use in this high-g arena. This paper describes the goals, objectives, and progress of the Hardened Subminiature Telemetry and Sensor System (HSTSS) program.
80

Spaceborne Video Interface Module (VIM)

Eason, Mark 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The use of video imaging in VME based data acquisitions systems is increasing. Some systems require the video data to be telemetered. In telemetry systems that require video data to be sent, a dedicated video data channel is common. It is the purpose of this paper to present the combination of a video interface and a video PCM channel into one module. The name of this project is "Video Interface Module" (VIM).

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