To see the other types of publications on this topic, follow the link: Determining center of gravity.
Dissertations / Theses on the topic 'Determining center of gravity'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Determining center of gravity.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Novotný, Michal. "Vliv uložení nákladu na bezpečnost jízdy nákladního vozidla." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-232467.
Full textAbstract:
The objection of this dissertation is to examine effects of stowed cargo on safety driving of a vehicle. Based on general experience of weighing trucks and monitoring of cargo fixture, my attempt was to summarize related legislative conditions of the operation of trucks in terms of payload, weighing and stowing of cargo. In the first part I worked on consistent methodology of stowing and fastening of cargo on trucks. I've included various methods of loading cargo and different ways of fastening and their calculations. The main body of the second part is a practical methodology of inspectional weighing of trucks on the road. In this section I took into account the current method and procedure of inspectional weighing and measuring of trucks. During my trial weighing of different types of trucks I proved that the key factor for safe seating and lashing of load on a vehicle is determining center of gravity of the vehicle. I solve this problem in detail in the last part of my work.
2
Andersson, Jonas. "Center of gravity analysis : an actual or perceived problem?" Thesis, Försvarshögskolan, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-1197.
Full textAbstract:
Centers of Gravity (CoGs) analyses deliver vital input to the operational design. However, there are a great number of theories regarding the phenomenon which can create a certain degree of confusion. The diversity in theories may lead to misdirected mental energy where the focus is to discuss theories instead of using the theories at hand efficiently. The question is if the diversity in theory is an actual problem or if it just perceived as such? This research identifies the similarities and differences in the theories of Milan Vego and Joseph Strange & Richard Iron regarding CoGs, their sub elements and methods for analysis. The impact of the differences on the practical result is then surveyed by implementing the theories on adelimitated phase of the Falklands War, in order to conclude if the differences have a decisive impact on the product of the CoG analysis. The result of this thesis indicates that the diversity in theory is a perceived problem. The identified divergence does not reflect crucially on the CoG analysis and the variation of the input provided to the operational design is minor. The CoGs and the critical vulnerabilities identified are the same or at least similar, no matter which of the two theories was used in this research.Avdelning: ALB – Slutet Mag. 3 C-upps. Hylla: Upps. ChP 07-09
3
Hack, Daniel E. "A cortical measure of the perceptual center of gravity." The Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=osu1406890046.
Full text
4
Kelly, Rodney D. "Center of gravity in the asymmetric environment : applicable or not? /." Thesis, Monterey, CA : Naval Postgraduate School, 2006. http://handle.dtic.mil/100.2/ADA457503.
Full textAbstract:
Thesis (M.A. in National Security Affairs) -- Naval Postgraduate School, June 2006.Thesis advisor : Richard Grahlman. "June 2006." Includes bibliographical references (p. 61-63). Full text available on Public Stinet.
5
Takada, Hiroki, Yoshiyuki Kitaoka, Satoshi Iwase, Yuuki Shimizu, Tomoyuki Watanabe, Meiho Nakayama, Masaru Miyao, and Koshin Mihashi. "Characteristic Changes of Sway of Center of Gravity with Advancing Afe." Research Institute of Environmental Medicine, Nagoya University, 2003. http://hdl.handle.net/2237/7608.
Full text
6
Cadwell, John Andres Jr. "Control of Longitudinal Pitch Rate as Aircraft Center of Gravity Changes." DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/426.
Full textAbstract:
In order for an aircraft to remain in stable flight, the center of gravity (CG) of an aircraft must be located in front of the center of lift (CL). As the center of gravity moves rearward, pitch stability decreases and the sensitivity to control input increases. This increase in sensitivity is known as pitch gain variance. Minimizing the pitch gain variance results in an aircraft with consistent handling characteristics across a broad range of center of gravity locations.
This thesis focuses on the development and testing of an open loop computer simulation model and a closed loop control system to minimize pitch axis gain variation as center of gravity changes. DATCOM and MatLab are used to generate the open loop aircraft flight model; then a closed loop PD (proportional-derivate) controller is designed based on Ziegler-Nichols closed loop tuning methods. Computer simulation results show that the open loop control system exhibited unacceptable pitch gain variance, and that the closed loop control system not only minimizes gain variance, but also stabilizes the aircraft in all test cases. The controller is also implemented in a Scorpio Miss 2 radio controlled aircraft using an onboard microprocessor. Flight testing shows that performance is satisfactory.
7
Price, Darryl Brian. "Estimation of Uncertain Vehicle Center of Gravity using Polynomial Chaos Expansions." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/33625.
Full textAbstract:
The main goal of this study is the use of polynomial chaos expansion (PCE) to analyze
the uncertainty in calculating the lateral and longitudinal center of gravity for a vehicle
from static load cell measurements. A secondary goal is to use experimental testing as a
source of uncertainty and as a method to confirm the results from the PCE simulation.
While PCE has often been used as an alternative to Monte Carlo, PCE models have
rarely been based on experimental data. The 8-post test rig at the Virginia Institute for
Performance Engineering and Research facility at Virginia International Raceway is the
experimental test bed used to implement the PCE model. Experimental tests are
conducted to define the true distribution for the load measurement systemsâ uncertainty.
A method that does not require a new uncertainty distribution experiment for multiple
tests with different goals is presented. Moved mass tests confirm the uncertainty analysis
using portable scales that provide accurate results.
The polynomial chaos model used to find the uncertainty in the center of gravity
calculation is derived. Karhunen-Loeve expansions, similar to Fourier series, are used to
define the uncertainties to allow for the polynomial chaos expansion. PCE models are
typically computed via the collocation method or the Galerkin method. The Galerkin
method is chosen as the PCE method in order to formulate a more accurate analytical
result. The derivation systematically increases from one uncertain load cell to all four
uncertain load cells noting the differences and increased complexity as the uncertainty
dimensions increase. For each derivation the PCE model is shown and the solution to the
simulation is given. Results are presented comparing the polynomial chaos simulation to
the Monte Carlo simulation and to the accurate scales. It is shown that the PCE
simulations closely match the Monte Carlo simulations.Master of Science
8
Barazanji, Deleer. "Model Based Estimation of Height of Center of Gravity in Heavy Vehicles." Thesis, KTH, Matematik (Inst.), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-92571.
Full textAbstract:
Abstract The center of gravity height in a vehicle a ects its dynamic driving properties but there is no accurate way of measuring the height of center of gravity today. One example of vehicle stabilizing systems is vehicle rollover warning and assist system which has to rely on a relatively accurate height of center of gravity estimate in order to be implemented in vehicles e_ciently and would otherwise be considered useless. In this thesis a literature study on the height of center of gravity in heavy vehicles in general and semitrailers in particular is conducted at Scania CV and emphasis is towards a model relying as little as possible on data from outside the tractor. A partly new model for detecting the vehicle's axle loads at di_erent acceleration values is developed and compared to other models, pros and cons are examined, furthermore an estimation tool is developed for the new model in a realistically applicable manner with regards to normal driving situations and solution limitations.The estimation tool is tested on Scania semitrailers with di_erent suspension con_gurations and the result shows that the height of center of gravity can be estimated as close as 4.1 (cm) from the real value for 4x2 Gen 2 Scania tractor and 3.3 (cm) for 4x2 Gen 3 Scania tractor.
9
Kimball, J. Allen. "America's two-front war : the American media assault on our center of gravity /." Norfolk, Va. : Joint Forces Staff College, Joint Advanced Warfighting School, 2006. http://handle.dtic.mil/100.2/ADA451319.
Full textAbstract:
Thesis (M.S. in Joint Campaign Planning and Strategy)--Joint Forces Staff College, Joint Advanced Warfighting School, 2006."14 April 2006." Vita. "National Defense Univ Norfolk VA"--DTIC cover. Includes bibliographical references (p. 71-77). Also available via the Internet.
10
Saeedkondori, Matin. "Estimation of the center of gravity of the human body using image processing." Thesis, California State University, Long Beach, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=1606699.
Full textAbstract:
Center of Gravity (COG) is an important parameter in many applications including aeronautics, astronomy, and kinesiology. This project focuses on the kinesiology application of the center of gravity, which helps people to understand their body’s stability and movement. The COG changes continually and does not have a fixed point inside the body. For example, in some exercises COG could be in the outer perimeter of the body.
In this project, we present an innovative approach to estimate the COG when the body is posed in an anatomical position. This approach uses image processing via MATLAB programing software. After preprocessing and processing of 2D images of the human body, we estimate the whole body’s COG in the three data sets. This project further considers alternate estimation in COG using reaction board technique, which allows us to estimate the accuracy of our method. In this project, the accuracy of the image processing COG estimation is 93% in compare to the reaction board. Finally, Body Mass Index (BMI) of the three data sets using the subject’s weight and height was calculated.
11
Ballaire, Frederic [Verfasser]. "Dynamic, Continuous, and Center of Gravity Independent Weighing with a Loader / Frederic Ballaire." München : Verlag Dr. Hut, 2015. http://d-nb.info/1080754288/34.
Full text
12
Cheng, Quan Jia. "A WLAN location estimation system using center of gravity as an algorithm selector." HKBU Institutional Repository, 2013. http://repository.hkbu.edu.hk/etd_ra/1513.
Full text
13
Badurdeen, Fathima Fazleena. "Determining optimal staffing levels for the picking and packing operations in a distribution center." Ohio : Ohio University, 2002. http://www.ohiolink.edu/etd/view.cgi?ohiou1174578669.
Full text
14
Good, R. J. "Computer program for determining the center of a permutation group in nearly linear time." The Ohio State University, 1993. http://rave.ohiolink.edu/etdc/view?acc_num=osu1406887590.
Full text
15
Ebert, Rebecca L. "Bridging Grammar and Speech Acoustics: Effects of Morpheme Status on Duration and Center of Gravity." Bowling Green State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1616618286162091.
Full text
16
Lashore, Michael. "Mathematical Model Validation of a Center of Gravity Measuring Platform Using Experimental Tests and FEA." DigitalCommons@CalPoly, 2015. https://digitalcommons.calpoly.edu/theses/1467.
Full textAbstract:
This thesis sets out to derive an analytical model for a center of gravity (CG) measuring platform and examines its validity through experimental testing and Finite Element Modeling. The method uses a two-stage platform tilting process to first locate the planar CG coordinates and then find the third CG coordinate normal to the platform. An uncertainty model of the measuring platform was also developed, both CG and uncertainty models were implemented in the form of a MATLAB code. A load cell sizing task was also added to the code to assist the Integration Engineers at Jet Propulsion Laboratory in selecting load cells to design their own version of the CG Platform. The constructed CG Platform for this project used an array of six strain gauges, four C2A-06-062LT-120 Tee Rosettes and two C2A-06-031WW-120 Stacked Rosettes. They were bonded onto the legs of three truss shaped bipods. Results from the Platform Tilting Tests could not be used to validate the CG model as the measured CG and weight values found from the experimental tests contained a considerable amount of error. The errors in the Platform Tilting Tests are believed to stem from the initial errors observed during the bipod rod and strain gauge calibration tests. As an alternative, an FE model of the CG measuring platform was created as another means of validation. The math model of the CG measuring platform was successfully validated by showing that there was less than a 0.01% different between the bipod loads predicted from the MATLAB code and the FE model. Using the FEM generated loads as inputs into the CG code to calculate a CG matched the initial point mass or CG created in the FE model within a 0.01% difference. To validate the CG model even further, another test should be performed using a CG Platform prototype instrumented with load cells to generate new experimental data and compare them with the results from the FE model.
17
Brooks, Steven D. "Evaluation of the base test method for determining the strength of standing seam roof systems under gravity loadings." Thesis, Virginia Tech, 1989. http://hdl.handle.net/10919/45958.
Full textAbstract:
The base tGSt method has been proposed by Carballo, Holzer and Murray [5] as a means of determining the strength of standing seam roof systems under gravity loading. The objective of this thesis is to evaluate the accuracy of the base test method. To do this, eleven sets of tests were performed at Virginia
Polytechnic Institute & State University (VPl&SU). Each test set consisted of a single span base test from which a failure load was predicted for the corresponding three span confirming test. Results of two test sets recorded in Reference [5] were also used to evaluate the method. A secondary objective of this thesis is to comment on the effects that system components (purlin orientation, clip type, bracing configuration, panel type, insulation and purlin type) have on the strength of the system. Results from proprietary tests conducted at VPI & SU were used in conjunction with the results from this research to accomplish the secondary objective.Master of Science
18
Wallace-Finney, Sheena R. "Determining the Optimal Aisle-Width for Order Picking in Distribution Centers." Wright State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=wright1312569054.
Full text
19
Sridhar, Siddharth. "Spacesuit and Portable Life Support System Center of Gravity Influence on Astronaut Kinematics, Exertion and Efficiency." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1447690750.
Full text
20
Roush, Grant Corwin. "Finding Cadaveric Human Head Masses and Center of Gravity: A Comparison of Direct Measurement to 3D ing." Wright State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=wright1282766380.
Full text
21
Mummidivarapu, Satya Sri. "A Method for Determining Body Weight Replacement Load during Squat Exercise in Weightlessness." University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1447690685.
Full text
22
Vaněček, Michal. "Měření polohy těžiště motocyklu." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-232692.
Full textAbstract:
My diploma thesis deals with measuring the center of gravity (CG) the motorcycle. The first part is outlined with legislation and the types of motorcycle division. I mention the theoretical types of measuring the CG the motocycle there too. These methods are applied to the issue of motor vehicles. The chosen one way of measuring the center of gravity which is used for practical measurements of gravity the motocycle. The practical part included the weighing of the different types of motorcycles with a different occupancy. These values are then processed and the resulting CG are calculated for each motorcycle. The values of CG were compared by experiment with the program for the analysis of road accidents and reconnoitred the measured results with this program results. In the last chapter is the evaluation of individual CG motorcycle and the influence of changes in occupancy due to a motorcycle.
23
VanDerBrink, Emily Marie. "Determining Barriers and Facilitators to Implementing the Resist Diabetes Intervention in Salem Veterans Administration Medical Center Patients." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/101819.
Full textAbstract:
With 47% of the veteran population aged 65 years or older, an age group with the highest prevalence of type 2 diabetes (T2D), prevention of T2D is critical within the Veterans Health Administration (VHA) system (1). Resist Diabetes (RD), a Social Cognitive Theory-based resistance training program, has been shown to reduce the prevalence of prediabetes by 34% in prediabetic older adults (2). The RD program could fill the gap within the VHA system for a structured diabetes prevention program not focused on weight, but instead focused on exercise. This thesis describes a mixed-methods investigation to determine what adaptations to the RD program are needed to implement the program within the Salem Veterans Affairs Medical Center (VAMC) patients. Salem VAMC care providers and veteran patients were recruited to gauge perceptions of the RD program, and identify barriers and facilitators to the referral process and program implementation. Semi-structured open-ended questionnaires and interview guides based upon the Consolidated Framework for Implementation Research (CFIR) (3) were utilized to determine major and minor themes within the provider and veteran responses. Quantitative data was also obtained to assess provider perceptions and participant characteristics. Major findings included: positive perceptions by providers for RD program acceptability, appropriateness and feasibility (4) within the Salem VAMC, positive perceptions of Intervention Characteristics of RD by veterans, major barriers to participation lied within the Outer Setting domain with travel, transportation, and time constraints. Major facilitators to program implementation lied within the Inner Setting domain with promotion by primary care. These findings could be used to inform a future version of the RD program adapted for the VHA system.Master of Science
24
Ballaire, Frederic [Verfasser], Steffen [Akademischer Betreuer] Müller, and Christian [Akademischer Betreuer] Schindler. "Dynamic, Continuous, and Center of Gravity Independent Weighing with a Loader / Frederic Ballaire. Betreuer: Steffen Müller ; Christian Schindler." Kaiserslautern : Technische Universität Kaiserslautern, 2015. http://d-nb.info/108082264X/34.
Full text
25
Deng, Shengfu. "A Spatial Dynamic Approach to Three-Dimensional Gravity-Capillary Water Waves." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/28254.
Full textAbstract:
Three-dimensional gravity-capillary steady waves on water of finite-depth, which are uniformly translating in a horizontal propagation direction and periodic in a transverse direction, are considered. The exact Euler equations are formulated as a spatial dynamic system in which the variable used for the propagating direction is the time-like variable. The existence of the solutions of the system is determined by two non-dimensional constants: the Bond number b and λ (the inverse of the square of the Froude number). The property of Sobolev spaces and the spectral analysis show that the spectrum of the linear part consists of isolated eigenvalues of finite algebraic multiplicity and the number of purely imaginary eigenvalues are finite. The distribution of eigenvalues is described by b and λ.
Assume that C1 is the curve in (b,λ)-plane on which the first two eigenvalues for three-dimensional waves collide at the imaginary axis, and that the intersection point of the curve C1 with the line λ=1 is (b0,1) where b0>0. Two cases (b0,1) and (b,λ) â C1 where 0< b< b0 are investigated. A center-manifold reduction technique and a normal form analysis are applied to show that for each case the dynamical system can be reduced to a system of ordinary differential equations with finite dimensions. The dominant system for the case (b0,1) is coupled Schrödinger-KdV equations while it is a Schrödinger equation for another case (b,λ) â C1. Then, from the existence of the homoclinic orbit connecting to the two-dimensional periodic solution (called generalized solitary wave) for the dominant system, it is obtained that such generalized solitary wave solution persists for the original system by using the perturbation method and adjusting some appropriate constants.Ph. D.
26
Said, Faozi. "An Evaluation of QuikSCAT UHR Wind Product's Effectiveness in Determining Selected Tropical Cyclone Characteristics." Diss., CLICK HERE for online access, 2009. http://contentdm.lib.byu.edu/ETD/image/etd3269.pdf.
Full text
27
Wallace, Rick L. "Planning for the Future: Determining the Effectiveness of Library Services to Medical Residents in an Academic Medical Center." Digital Commons @ East Tennessee State University, 2006. https://dc.etsu.edu/etsu-works/8784.
Full text
28
Moody, Julie Anne Moody. "Determining Caregiver Understanding of Childhood Asthma Control and Preferred Mode of Communication in a School based Health Center." Xavier University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=xavier1524760698798185.
Full text
29
Dubuque, Elise(Elsie S. ). "Multifamily Amenity Wars : defining their current state in luxury urban markets and determining impacts of COVID-19." Thesis, Massachusetts Institute of Technology, 2020. https://hdl.handle.net/1721.1/129092.
Full textAbstract:
Thesis: S.M. in Real Estate Development, Massachusetts Institute of Technology, Program in Real Estate Development in conjunction with the Center for Real Estate, September, 2020Pagination: 1-123, 142-146, 124-141. Cataloged from student-submitted PDF of thesis.
Includes bibliographical references (pages 144-146).
This paper examines the historic, current and future state of luxury residential amenities and the popularly-called "Amenity Wars" in luxury multifamily housing. The research is based on U.S. urban markets with a special focus on Boston, Massachusetts, where the recent building boom and overall healthy economy have created an active and competitive multifamily development environment. It also aims to answer the question: how has/will COVID-19 (coronavirus disease 2019) impact the thinking behind and programming of residential building amenities? The discussion of recent Amenity Wars trends incorporates themes such as catering to resident needs on a lifestyle level; the draw of physical amenities vs. service-oriented amenities; and demographic and market conditions that have resulted in the current state of multifamily demand.
Following is an exploration of how, as of summer 2020, the coronavirus's rapid person-to-person spread has proved particularly disruptive to the way multifamily housing operates, and how it has challenged existing perceptions about what makes for a desirable multifamily housing experience. The experience of the COVID-19 pandemic will represent a profound moment in collective memory with the power to alter not only the planning and programming of multifamily features and amenities, but luxury urban residential demand in general. As such, it is now time to rethink what the future of the Amenity Wars will look like in both the evolving new normal and long-term new normal. This paper demonstrates how, during the pandemic, innovative designs and other creative solutions have already begun to infiltrate multifamily design and construction.
It also establishes that a healthy demand for luxury urban multifamily housing is poised to remain in the long term, along with which additional notable shifts in multifamily feature and amenity programming will occur. Going forward, we should expect to see changes to physical space in the form of more spatially-adaptable buildouts that enable flexibility of use in addition to more private areas and less community focus, as well as a shift toward service over some physical amenities. Additionally, some of the most lasting effects of the pandemic will be in regard to how multifamily buildings are designed to accommodate new demands of teleworking.
by Elise Dubuque.
S.M. in Real Estate Development
S.M.inRealEstateDevelopment Massachusetts Institute of Technology, Program in Real Estate Development in conjunction with the Center for Real Estate
30
Bendapudi, Srinivas, and Mayil Murugan Shiva Kumar Patchai. "Design of Station for Calculating Centre of Gravity of Truck Cabin : A Product Design Project." Thesis, Linköpings universitet, Maskinkonstruktion, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-148599.
Full textAbstract:
As a part of Linköping University’s master program course curriculum, current thesis is performed at Tools and fixtures department (MPCT) of Scania, Oskarshamn. The aim of this master thesis project is to develop a complete construction of the station in CAD which calculates the weight and center of gravity of all the different cabs produced in Scania CV AB. To accomplish this project a generic product development process described in product development textbook by Ulrich and Eppinger (2012), fifth edition and The mechanical design by David G Ullman, fourth edition were extensively used. The whole function from a black box is decomposed into several sub functions and different solutions were identified for these individual functions. By using morphology matrix and proper combinations from these solutions five different concepts were developed and presented to Scania CV AB. The team along with technical design experts in the MPCT department evaluated all the concepts and one concept was chosen for further development. Protecting the weighing scales during loading of cab from forklift onto the station and safety for the cab during tilting are the two main challenges faced during detail design phase. We were able to achieve these operations by incorporating a lifting table into the station design. Thanks to the custom made multi-tasking lift table which is manufactured and supplied by HYMO. With the help of sensors, speed of the lifting table can be controlled with two operating speeds-High & Low. Lifting table moves in its lowest speed whenever it approaches the weighing scales. Incorporation of Jacob safety into the lifting table allows the table to always operate in low speed when the lift link is in action. These sensors ensure high safety for the cab and weighing scales. Apart from this, an emergency stop has been provided to stop the entire operation in case of emergencies. In this proposed design, the center of gravity values will be determined in two stages and the weight readings are recorded in computer during these stages. For determining the longitudinal and transverse distances of CG, weight readings from all the weighing scales is essential once the cab is loaded on the station from the forklift. For determining the vertical distance of CG, two weight readings and measured tilt angle is required. A calculation module will allow the user to enter these values and obtain the result in no time. This developed 3-D CAD model with 2-D drawings are presented to Scania and the obtained results of this work fulfilled the set of requirements set for this master thesis.
31
Grould, Marion. "Études d'effets relativistes au Centre Galactique à l'aide de simulations d'observations d'orbites d'étoiles par l'instrument GRAVITY." Thesis, Paris Sciences et Lettres (ComUE), 2016. http://www.theses.fr/2016PSLEO013/document.
Full textAbstract:
Le Centre Galactique abrite en son cœur un objet compact de plusieurs millions de masses solaires. L'hypothèse faite à l'heure actuelle est que cet objet serait un trou noir supermassif décrit par la relativité générale. L'instrument de seconde génération du Very Large Telescope Interferometer, GRAVITY, va permettre d'apporter des réponses quant à la réelle nature de cet objet. Grâce à sa précision astrométrique de 10 microsecondes d'angle, il va pouvoir sonder l'espace-temps en champ fort via l'observation des étoiles et du gaz situés à proximité de l'objet central.Au cours de ma thèse j'ai mis au point un modèle permettant de simuler les observations d'orbites d'étoiles de GRAVITY, l'objectif étant d'extraire à l'aide de celui-ci les paramètres fondamentaux du candidat trou noir central ainsi que les effets relativistes. Pour cela, j'ai utilisé le code de tracé de rayons GYOTO développé à l'Observatoire de Paris. Ce code permet de calculer des trajectoires d'étoiles et de photons obtenues en présence d'un objet compact. Il est alors possible de simuler les positions apparentes d'étoiles en orbite autour du Centre Galactique en calculant leur image relativiste.J'ai d'abord validé le calcul des trajectoires des photons effectué dans GYOTO. Grâce à des tests effectués en déflexion faible et forte, j'ai pu démontrer que GYOTO était hautement satisfaisant pour simuler les observations GRAVITY. En effet, j'ai montré que l'erreur sur le calcul des géodésiques de genre lumière était inférieure à environ 10^-2 microseconde d'angle, et cela même pour de grandes distances d'intégration.Je me suis ensuite intéressée à l'étude d'une étoile appelée S2 qui a contribué à fortement contraindre la masse de l'objet central. Sa proximité au Centre Galactique fait d'elle une cible idéale pour sonder l'espace-temps en champ fort. En particulier, j'ai estimé quels étaient les temps minimaux d'observation nécessaires pour détecter des effets relativistes à l'aide de mesures astrométriques et spectroscopiques obtenues sur l'étoile S2. Pour cela, j'ai mis en place plusieurs modèles d'orbites prenant en compte chacun un certain nombre d'effets relativistes. Le modèle le plus précis est obtenu en relativité générale complète avec le code GYOTO. Néanmoins, puisque l'étoile S2 est suffisamment éloignée de l'objet compact, ce modèle néglige certains effets de lentilles gravitationnelles telles que les images secondaires et l'amplification des images primaires. Par ailleurs, je me suis également intéressée à la contraindre du moment cinétique du candidat trou noir central avec cette étoile. En particulier, j'ai déterminé, grâce au modèle le plus précis mis en place ici, qu'il était possible de contraindre la norme et la direction du moment cinétique avec une incertitude d'environ 0,1 et 20 degrés, respectivement, et cela en considérant des observations obtenues sur trois périodes de S2 et des précisions de 10 microsecondes d'angle et 10 km/s.En vue de la possible détection d'étoiles plus proches du Centre Galactique par GRAVITY, j'ai développé un modèle prenant en compte les effets de lentilles négligés dans le modèle précédent. Néanmoins, afin de minimiser le temps de calcul demandé par celui-ci, j'ai déterminé une zone de l'espace dans laquelle il était tout de même possible d'utiliser ce dernier.Enfin, j'ai étudié l'influence de corps du Système Solaire sur les mesures astrométriques de GRAVITY, c'est-à-dire sur la séparation angulaire entre deux sources du Centre Galactique. Cette étude a montré que ces mesures différentielles n'étaient déviées que de quelques microsecondes d'angle par la perturbation gravitationnelle engendrée par le Soleil. Cependant, celles-ci sont modifiées de plusieurs centaines de microsecondes d'angle par l'effet d'aberration induit par le mouvement de la Terre par rapport aux sources du Centre Galactique. Il sera donc nécessaire de prendre en compte cet effet lors de l'interprétation des données obtenues par GRAVITYDecades of studies have demonstrated the presence of a compact object of several million solar masses at the center of the Galaxy. Nowadays, the assumption is that this compact object is probably a supermassive black hole described by general relativity. The second generation instrument at the Very Large Telescope Interferometer, GRAVITY, is expected to better constrain the nature of this central object. By using its astrometric accuracy of about 10 microarcseconds, it will probe spacetime in strong gravitational fields by observing stars and gas located near the compact object.During my PhD I have developed a stellar-orbit model in order to interpret the future GRAVITY observations. By using this model it will be possible to extract the central black hole candidate parameters and relativistic effects. To implement the model, I used the ray-tracing code GYOTO developed at Observatoire de Paris. This code allows computing star and photon trajectories obtained in the vicinity of a compact object. It is thus possible to simulate apparent positions of stars orbiting the Galactic Center by computing relativistic images.My work started by validating the photon trajectories computed in GYOTO. By doing tests in both weak- and strong-deflection limits, I have shown that the GYOTO code is highly qualified to simulate GRAVITY observations. Indeed, the error made on the photon trajectories is inferior to 10^-2 microarcsecond, even when integrating over large distances.Then, I was interested in studying a star called S2 that contributed to importantly constrain the mass of the central object. This star is the second closest star to the Galactic Center and has an orbital period of about 16 years. Nowadays, we do not know whether closer-in stars will be discovered by GRAVITY. It is thus important to extract as much information as possible from this star. In particular, I have estimated the minimal observation times needed to detect relativistic effects by using astrometric and spectroscopic measurements of S2. To do so, I have developed different stellar-orbit models taking into account a certain number of relativistic effects. The more accurate model is obtained by using the ray-tracing code GYOTO and considering all relativistic effects. However, as the S2 star is sufficiently far from the compact object, this model neglects certain gravitational lensing effects such as the secondary images and the primary images amplification. Besides, I was also interested in the possibility of constraining the angular momentum of the central black hole candidate with the S2 star. In particular, I have shown that with a model which does not use ray-tracing, the norm and the direction of the angular momentum can be constrained with an uncertainty of about 0.1 and 20 degrees, respectively, by using observations obtained during three periods of S2 and with accuracies reaching 10 microarseconds and 10 km/s.Since closer-in stars could be detected by GRAVITY, I have developed a more accurate stellar-orbit model taking into account the lensing effects neglected in the previous model. However, in order to minimize the computing time required by this model, I determined a volume in which it is possible to neglect both the secondary images and the primary images amplification.Finally, I have studied the impact of different components of the Solar System on astrometric positions measured by GRAVITY. This study has shown that those measurements are deviated by an amount of a few microarcseconds by the gravitational perturbation generated by the Sun. However, those apparent positions are shifted by several hundred microarcseconds by the aberration effect due to the movement of the Earth with respect to the Galactic Center. It is thus necessary to take into account this effect in future interpretations of GRAVITY observations
32
Chai, Sonny T. "Landing gear integration in aircraft conceptual design." Thesis, This resource online, 1996. http://scholar.lib.vt.edu/theses/available/etd-09182008-063506/.
Full text
33
Rücker, Jan. "Měření hmotnostních parametrů vozidel." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-232657.
Full textAbstract:
This thesis is the first part deals with methods of determining weight parameters of vehicles. By measuring the position of center of gravity and inertia measurements. In the second part focuses on the measurement of gravity position in a selected group of vehicles Škoda and their comparison between vehicles and comparison with simulation programs PCcrach and Virtual crach.
34
Náglová, Katarína. "Konvenční a adaptivní metody nastavení parametrů regulátoru pro řízení letové výšky letadla s pohyblivou pozicí těžiště v prostředí MATLAB - Simulink." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-219931.
Full textAbstract:
The thesis is focused on aircraft flight level control in case when the location of center of gravity changes during flight. The theoretical part of the thesis describes basics of aerodynamics, which are necessary to understand airplane's behavior and its control theory. Basics of state theory and stability of systems, as it is used for design of linear model. This part also mentions mathematical equations of nonlinear model of business jet and discusses conventional and adaptive methods used to design autopilot parameters. Several autopilots were designed in practical part of the thesis. The most important part is the logic used to determine location of center of gravity of the airplane. The models use nonlinear model of an airplane that better represents the real environment and conditions.
35
Dvořák, Karel. "Měření setrvačných charakteristik těles pro účely matematického modelování dynamiky vozidel." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-227970.
Full textAbstract:
The aim of the diploma thesis is to create a concept of methods that can be used for measurement of important mechanical inertia properties of bodies -- the coordinates of center of gravity and the the moment of inertia tensor, in case we don't have 3D model of these bodies. The thesis divides this problem into several sub-problems and suggests the solutions for each of them. Required equipment was created and measurement was carried out. At the end the measured values are compared with the teoretical ones and accuracy of this method is determined.
36
Dušek, Otakar. "Vliv hmotnostních parametrů vozidel na jízdní dynamiku." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-241368.
Full textAbstract:
This diploma thesis deals with assessment of weight parameters impact on driving dynamics. History and basic categories of personal vehicles are described in the introductory part. Weight parameters and driving dynamics of personal vehicles are described in the next part. Methodology and results of realized driving tests (braking test, circular test and avoidance maneuver) are presented in the experimental part of this work. Simulation of realized driving tests that was made by simulation software Virtual Crash is devised in the penultimate chapter. Evaluation of results that were found out from realized and simulated driving tests is made in the last chapter. Achieved results are briefly summarized in conclusion.
37
Kunovský, Martin. "Vliv polohy těžiště vozidla na jeho postřetový pohyb." Master's thesis, Vysoké učení technické v Brně. Ústav soudního inženýrství, 2012. http://www.nusl.cz/ntk/nusl-232690.
Full textAbstract:
This diploma thesis analyses the influence of the change to the vehicle’s center of gravity on its after-impact movement. The theoretical part of the thesis describes the basic methods which are used in investigation of the transverse, lengthwise and height position of center of gravity or the influence of center of gravity’s vehicle position to its stability and handling. Next part of the thesis deals with basic division of the road accidents and briefly describes the methods used in its analysis. Problematic maneuvers and everyday road traffic situations are stated in this thesis. Chosen situations were simulated in Virtual CRASH and PC crash programmes. Influence of the transverse, lengthwise and height position of center of gravity was investigated in these programmes with regards to the after-impact behaviour of vehicle. The obtained results were evaluated in the final chapter.
38
Reed, Linda E. "Determining the Relationship Between Motivation and Academic Outcomes Among Students in the Health Professions." Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc3624/.
Full textAbstract:
Admissions processes for health professions programs result in students entering these programs academically homogeneous. Yet some students have great difficulty with the programs. Research has shown a limited ability of traditional academic indicators to predict successful outcomes for health professions education. The purpose of this study was to examine the relationship between learning motivation and academic outcomes for students in health professions programs. The Modified Archer Health Professions Motivation Scale (MAHPMS) and a demographic survey were administered at orientation to 131 medical and 29 physician assistant students at the University of North Texas Health Science Center in the fall of 2005. At the end of the semester, the same version of the MAHPMS was administered, and final course grades and semester averages were collected. Descriptive statistics were analyzed for all the study variables. Analysis of variance was utilized to examine within subjects and between subjects differences for the learning motivation scores among programs and demographic categories. Linear regression analyses were used to determine the relationship between learning motivation scores and end-of-semester grades. And finally, logistic regression was performed to explore the ability of the motivation scores to predict academically high-risk students. Approximately three-fourths of the students indicated a preference for mastery learning and an internal locus of control. For the PA students, alienation to learning and performance goal scores statistically related to semester grades, and alienation to learning scores predicted high-risk academic performance almost 90% of the time. For the medical students, mastery goal scores statistically related to semester grades, but no motivation score predicted high-risk performance. External locus of control scores predicted high-risk performance 81% of the time for the total group of students at the end of the semester. Students in this study exhibited learning motivation preferences similar to those of other health professions students reported in the literature. The findings of this study agreed with the literature on achievement motivation theory and raised questions regarding the effect of health professions curricula on student learning goals. Similar studies, measuring larger samples longitudinally need to be conducted in order to further validate or elucidate the results of this study.
39
Kutluay, Emir. "Identification Of Inertia Tensor Of Vehicles." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/3/12608796/index.pdf.
Full textAbstract:
The aim of this thesis is to develop a methodology for obtaining mass properties of a vehicle using specific test rig. Investigated mass properties are the mass, location of center of gravity and the inertia tensor. Accurate measurement of mass properties of vehicles is crucial for vehicle dynamics research. The test rig consists of a frame on which the vehicle is fixed and which is suspended from the ceiling of the laboratory using steel cables. Mass and location of center of gravity are measured using the data from the test rig in equilibrium position and basic static equations. Inertia tensor is measured using the data from
dynamical response of the system. For this purpose an identification routine which employs prediction error method is developed using the built&ndashin functions from the System Identification Toolbox of MATLAB®
. The experiment was also simulated using Simmechanics Toolbox of MATLAB®
. Identification code is verified using the results of the experiment simulations for various cases.
40
Zamazal, Jakub. "Návrh rekonstrukce střední části trupu letounu Z 143 náhradou za poloskořepinu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318137.
Full textAbstract:
The thesis is focused on reconstruction of middle part of fuselage Z 143 aircraft from truss frame to semi-monocoque frame. In the thesis there is a conceptual design of semi-monocoque middle part of fuselage. The spars of centre wing section are strength controlled. In thesis there is weight analysis according to use the semi-monocoque middle part of fuselage. In second half of the thesis there is a study of retractable landing gear. The thesis shows weight savings according to use a semi-monocoque frame. The thesis also shows that semi-monocoque frame allows other option to upgrade Z 143 aircraft. This thesis can serve as a feasibility study of the reconstruction of the middle part of the fuselage Z 143 aircraft.
41
Harris, Sheryl. "Determining the Reliability and Use of the Center for Community College Student Engagement Survey of Entering Student Engagement As a Tool to Predict Student Success in a Large Urban Community College District." Thesis, University of North Texas, 2014. https://digital.library.unt.edu/ark:/67531/metadc699936/.
Full textAbstract:
As community colleges have gained more recognition as a viable pathway for students to enter higher education, they have faced greater accountability that has prompted both practitioners and policy makers to attempt to find solutions and tools, such as National Survey of Student Engagement, Community College Survey of Student Engagement, and Survey of Entering Student Engagement (SENSE), to aid in improving student success outcomes. This study addressed the validity and reliability of the SENSE instrument using a three-pronged approach via student data collected over 3 years of SENSE administrations at a large urban community college (n = 4,958). The instrument was first factor analyzed against the SENSE benchmarks for effective educational practice through generalized least squares and principal component exploratory factor analysis. Although the instrument did not deliver a chi-square factored fit for the six benchmark categories, consistent loadings were observed. Second, construct reliability was tested for each benchmark category, and the survey as a whole using Cronbach’s alpha. All categories did not yield sufficient coefficient scores for establishing construct reliability. However, the overall survey produced a Cronbach’s alpha of .85, clearly indicating construct reliability for all items combined. Third, correlations between SENSE perception scores and community college students’ grade point averages, fall to fall retention, semester credit hours, course completion for developmental and college gateway courses, and degree and certificate completion were calculated. Although no strong correlations were observed, the SENSE may be useful to community colleges seeking to increase completion rates.
42
Isselmou, Braham Braham Cheikh Baye. "Les pêcheries pélagiques de la ZEE mauritanienne : nouvelles méthodes pour de nouvelles connaissances." Thesis, Montpellier 2, 2013. http://www.theses.fr/2013MON20248/document.
Full textAbstract:
Les contextes national et international sont marqués par une prise de conscience de plus en plus grande de l’importance du poisson pour la sécurité alimentaire des populations des pays sous-développés. En Mauritanie, les petits pélagiques constituent une source de protéines animales accessibles aux faibles pouvoirs d’achat et contribuent à garantir la sécurité alimentaire de nombreuses populations. Malgré la présence d’une variabilité naturelle importante des espèces pélagiques, ce travail de thèse montre qu’il existe des éléments de stabilité dans l’écosystème pélagique dans la zone nord-ouest africaine. L’hypothèse de la présence des stocks sédentaires au niveau des zones de nourriceries en Mauritanie et au Sénégal est démontrée. La répartition spatio-temporelle des sardinelles en relation avec la dynamique de l’océan (upwelling, température de surface et chlorophylle) a été examinée. L’analyse des statistiques de la pêche sur une série de plus de trente (30) ans ne soutiennent pas l’immigration en provenance du Sénégal vers la Mauritanie d'Avril à Septembre selon l’hypothèse de Boëly (1978). Ce travail de thèse examine des hypothèses de migrations possibles des sardinelles dans la zone nord-ouest africaine et d’importantes implications en matière de gestion sont discutées. Pour finir, ce travail est replacé dans son contexte plus global de l’aménagement de la pêcherie des petits pélagiques. De nouvelles perspectives pour l’application des techniques géostatistiques (indicatrices et co-krigeage) et modélisation statistique sont envisagées pour l’étude de la dynamique des stocks des sardinelles et chinchardsNational and international context marked by an awareness of growing importance of pelagic fish for food security of people in underdeveloped countries . The depletion of demersal species also makes this extremely important resource for the future pelagic fisheries in Mauritania. Mauritanian EEZ is characterized by the existence of a favorable development of several species hydro-climatic and morphological phenomena , small pelagic species that represent more than 90% of the fisheries potential is about one million tones. The major problems facing the management of these species is understanding the roles played by them in their biogeography intrinsic spatio- temporal dynamics ( short-lived , aggregation , etc. ..) and the evaluation of their abundances . Assessment of exploited fish stocks is a priority. However, the recurring difficulty of evaluations of these fisheries, naturally very unstable, often reflected a lack of precision in the methods used , the incompleteness of the data ( which is also a problem of sampling) or sampling uncontrolled .The Mauritanian small pelagic fisheries are multi-species (sardines , horse mackerel , sardinella ) . In addition to the data provided by the logbooks including the holding is mandatory for industrial units, survey data for the landing craft and coastal segment often used to calculate the abundance, acoustic surveys , are an important means for quantify the abundance and study the distribution of these resources. The data collected by observers on board fishing industrial units are also a source of important information.Based on these data , this work aims at the reconstruction of the main series of abundances of small pelagic stocks in the northern part of West Africa , to be used in the adjustment of stock assessments models. Given the importance of the environmental component in very large fluctuations observed, the integration of this dimension in the analysis of this series catches the role of each of these factors (fisheries and environment) in the variability of abundance seasonal and amplitude of their migration.In addition to these conventional data Mauritania introduced on board commercial fishing vessels with VMS . This system allows the transmission by satellite to the body control the ship's position every hour is an important technological advance. This new type of data could therefore be a new source for estimating abundance and fishing effort of small pelagic species through appropriate statistical methods. A method for the interpretation in terms of paths abundance index was applied. The coupling of VMS and logbook will help to improve the definition of nominal fishing effort and catch location at fine spatial and temporal.The general problem is how to improve the estimation of the abundance of small pelagic stocks , understand fluctuations in the abundance and migration strategy of the species as well as tactics and strategies implemented by fleets to fish resources whose behavior is often erratic . It is therefore to adresse several issues in particular:What is the trend of the evolution of the abundance of pelagic species in the North West African area? The interpretation of the trajectories in terms of VMS fishing can it be used to map the abundance of key species? What are the seasons abundances? Environmental parameters they play an important role on the distribution of species? Will there a difference between tactics and strategies of the different fleets fishing for small pelagic? Data logs and data collected by observers on board can be used as a priori knowledge? To address these issues , we proceed to the mobilization of all relevant time series and implement innovative statistical and geostatistical methods , some of which applied for the first time in the sub -region for these stocks
43
Toman, Josef. "Zařízení pro měření výškové polohy těžiště vozidla." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231246.
Full textAbstract:
This diploma thesis deals with measurement of vehicle centre of gravity height position. In the first part is created summary of methods used for measuring centre of gravity position and moment of inertia of the vehicle. In the other parts are designed and analyzed two dynamics method of measuring centre of gravity height position. This thesis presents analysis of the errors of the proposed methods, results of measurements and design of the construct adjustments device for measuring of the moments of inertia enabling its used for measuring centre of gravity height position. Some components are through analyse of tension.
44
Magnét, Erik. "Att hitta akilleshälen : sårbarhetsanalyser till stöd för militär planering." Thesis, Försvarshögskolan, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-7559.
Full textAbstract:
Enligt gällande västliga militära planeringsdoktriner, inklusive den svenska som den formuleras i Svensk planerings och ledningsmetod (SPL), är tyngdpunktsanalyser av såväl motståndaren som den egna sidan avgörande steg i planeringsprocesserna på både strategisk och operativ nivå. Tyngdpunkten kan anfallas eller påverkas direkt eller indirekt, i det ideala fallet genom att slå mot kritiska sårbarheter. Kritiska sårbarheter kan ofta vara av teknisk karaktär, vilket historiska erfarenheter visar. Bristande teknisk förståelse riskerar därmed leda till att kritiska sårbarheter hos fienden inte exploateras och att våra egna inte skyddas. De nyckelfaktorer som bygger upp tyngdpunkten ska enligt doktrinerna identifieras genom systemanalys. Beskrivningarna av vad en systemanalys är eller hur denna kan genomföras saknar dock både tillräckligt djup och tydlighet för att kunna användas praktiskt och ge önskad kvalitet. Detta riskerar att ge stora konsekvenser för den fortsatta planeringen. I uppsatsen föreslås en utvecklad metod för tyngdpunktsanalys, med fokus på hur de kritiska sårbarheterna identifieras och värderas. Metodens huvudsakliga moment är modellering och klassificering, där klassificeringsmomentet sker med en föreslagen metod som hämtat stöd från såväl verkansprocessen som civil forskning om systemsårbarheter. Metoden operationaliseras i uppsatsen och prövas i en fallstudie med två fall. Slutsatserna från undersökningen indikerar att den föreslagna metoden är användbar och har förklaringskraft i de undersökta fallen. För att analysen av kritiska sårbarheter ska nå tillräcklig kvalitet krävs djupa systemkunskaper och inte minst resurser i form av personal och tid. Den föreslagna metoden behöver prövas i sin helhet för att utvärdera den praktiska användbarheten.According to contemporary western military doctrines, and Swedish doctrine is no exception, analyses of the centers of gravity of enemy and friendly forces are vital steps in the planning process at the strategic and operational levels of war. Centers of gravity might be attacked or influenced directly or indirectly, ideally by targeting critical vulnerabilities. Critical vulnerabilities are often of a technical nature, as shown by historical experience. A lack of technical understanding might lead to enemy vulnerabilities not being exploited and our own not being adequately protected. According to doctrine, a center of gravity’s key factors should be identified through systems analysis of enemy and friendly forces. However, descriptions of what these analyses are, or how they should be conducted, lack sufficient depth and clarity to be used in practice and provide sufficient quality. This is likely to have negative consequences for continued planning. This thesis proposes a developed method for center of gravity analysis, focusing on the identification and evaluation of critical vulnerabilities. The main elements of the method are modeling and classification, where the classification is conducted using a proposed method, supported by a method within the targeting process, and by civilian research into system vulnerabilities. The full method is operationalized in the thesis and tested in a two-case study. The conclusions from the study indicate that the proposed method is usable and has explanatory value in the cases studied. To achieve sufficient quality in the analysis of critical vulnerabilities, in-depth systems knowledge and, not least, resources in terms of staff and time are required. The proposed method needs to be tested in its entirety to evaluate its practical usability.
45
Rensa, Pavel. "Návrh koncepce systému vztlakové klapky pro novou generaci sportovního letounu." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2010. http://www.nusl.cz/ntk/nusl-228926.
Full textAbstract:
ploma thesis deals with design of a four-seat sport aircraft for basic training, tourist flying and glider towing, which can be used in aeroclubs and by private owners. The objective of this thesis was to design the outer shapes of the aircraft, compute the basic aerodynamic characteristics and performance, design of structural and aerodynamic layout of the wing and design of flap system with governing.
46
Bilík, Martin. "Monitorování hazardního prostředí." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2011. http://www.nusl.cz/ntk/nusl-229953.
Full textAbstract:
Diploma thesis Monitoring of hazardous environment deals with possibilities of construction of monitoring device for the nuclear power station Temelín. In the first part are accurate requirements for monitoring device, individual risks and identify obstacles and opportunities how to overcome them. There is also description of basic options for measuring temperature and environmental monitoring. Using multi-criteria analysis was done the selection of all components, from which is possibility to construct the first development release of monitoring device. 3D models for each component and the overall design visualization facilities were created in the programming environment of Autodesk Inventor. The conclusion provides an overview of the financial cost of the equipment is assembled
47
Jurkštas, Kęstutis. "Sklandytuvo svorio centro padėties įtakos skrydžio charakteristikai analizė." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2011~D_20110830_152339-05498.
Full textAbstract:
Standartinės klasės sklandytuvo SZD – 48 – 3 “Jantar Standard 3” optimalios svorio centro padėties radimas. Pateikta skaičiavimai optimaliai svorio centro padėčiai surasti bei jos kitimas kintant greičiui.The objective of this Master thesis is to investigate the glider gravity centre influence to the flight characteristics. Analyzing Frank Irving method, to find optimal centre of gravity. The subject of thesis is Standard class glider SZD – 48 – 3 “Jantar Standard 3”and calculation of optimal center of gravity position.
48
Bazert, Cédric. "Influence de l’avancement de la mandibule sur la posture générale : étude stabilométrique et compléments électromyographiques." Thesis, Bordeaux 1, 2008. http://www.theses.fr/2008BOR13755/document.
Full textAbstract:
Les orthèses de propulsion mandibulaire sont fréquemment utilisées en orthopédie-dento-faciale pour stimuler le développement de ce maxillaire. Le déplacement antérieur de son centre de gravité et les tensions musculaires et viscérales (appareil aéro-digestif) qui apparaissent alors sont susceptibles d’influer sur la posture du sujet debout. Pour le déterminer, une étude stabilométrique a été menée. Elle permet de mettre en évidence les variations de position de la projection au sol du centre de gravité du corps (PGv). Les effets du port de trois orthèses imposant une quantité de propulsion différente ont été analysés, comparés entre eux et à la situation sans orthèse portée. Ces résultats ont été complétés par ceux issus d’une étude électromyographique, menée pour détecter les muscles mis en jeu dans le contrôle de l'équilibre. L’ensemble de ces expérimentations montre principalement une perte du contrôle postural (augmentation des oscillations de PGv) et un repositionnement plus postérieur du centre de gravité corporel lors d’avancement mandibulaire important, et ce d’autant plus que l’orthèse portée provoque peu de désocclusion inter-maxillaire. Une activité accrue des muscles fléchisseurs dorsaux du pied, de la hanche, du cou et extenseurs du rachis lombaire accompagne ces variations de position de PGv. Une hypothèse d'adaptation posturale en réaction à l'avancement de la mandibule est formulée ainsi qu’une critique et une évolution du protocole d’étudeMandibular propulsion splints are frequently used in dento-facial orthopedics so as to stimulate the development of this maxilla. Consequently, we can notice that its centre of gravity moves forward but also that visceral (the aerodigestive apparatus) and muscle tensions appear. These elements are likely to have an influence on the position of a person standing. A stabilometric study was carried out to highlight the changes in the projection onto the ground of the body centre of gravity (PGv). We analysed and compared the effects of the wearing of three different splints (each of which required a different level of propulsion). But a comparison between these results and the normal situation (no splint worn) was also drawn. Moreover, an electromyographic study was carried out to find out which muscles were stimulated in the balance control. Its results were then added to those of the stabilometric study. These experiments mainly show that we lose control of the postural equilibrium (increase of the PGv oscillations). It also shows that when the mandible is significantly moved forward, the body center of gravity goes back into a more posterior position. This is all the more true as the splint worn does not cause much inter-maxillar disocclusion. The back flexor muscle of the foot, of the hip, of the neck and the extensor muscle of the lumbar rachis are greatly stimulated in the variations of the PGv. A postural adaptation to the mandibular advancement is hypothetically expressed, together with a criticism and an evolution of the study procedure
49
Bele, Daniel. "Warden i Israel : En studie av Wardens tillämpning i Israels luftkrig 2006-2009." Thesis, Försvarshögskolan, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:fhs:diva-4053.
Full textAbstract:
Den amerikanske luftmaktsteoretikern John A Warden III har skrivit ett flertal artiklar och böcker om vad han anser är det bästa sättet att använda luftmakt. Warden förordar luftmaktens offensiva natur och eftersträvar ett snabbt, för egen del, fördelaktigt slut på en konflikt. Warden har bl.a. liknat fienden vid ett system, där han menar att strävan skall ligga i att slå ut fiendens ledarskikt vilket får tillföljd att dess vilja till strid upphör. I detta arbete ges en sammanfattning av, enligt författaren, centrala delar av Wardens teorier. Sammanfattningen mynnar ut i tre stycken parametrar som kommer att utgöra Wardens teorier i detta arbete. De tre parametrarna är "enemy as a system", "center of gravity" samt "parallell attack". Dessa parametrar ligger sedan till grund för en analys av Israels luftkampanjer i dess krig mot Hizbollah 2006, Operation Change of Direction samt dess krig mot Hamas 2008-09, Operation Cast Lead. Syftet med detta är att ta reda på om Israel använde sig av Wardens teorier under dessa båda operationer. Anledningen till valet av dessa två konflikter är att Israel bl.a. sin doktrin slagit fast att de aldrig har råd att förlora ett krig. Detta tvingar Israel att optimera sin taktisering. Slutsatsen blev att det tydligt går att se att Wardens teorier genomsyrade Operation Change of Direction. Det var enbart "parallell attack" som inte tydligt efterföljdes genom hela operationen. Under Operation Cast Lead däremot så följde Israel Wardens teorier i mycket mindre utsträckning. Det var enbart "center of gravity" som följdes genom hela den operationen.
50
Kóňa, Marián. "Aerodynamický návrh transsonického bezpilotního kluzáku." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-232008.
Full textAbstract:
This master thesis is focused on aerodynamic design of transonic glider, which is assigned for following an airliner at cruising regime of flight. Main goal of the thesis is to determine basic geometrical design of airplane with respect to Whitcomb aera rule, mass analysis and drag polar. Weight analysis includes determining center of gravity according to longitudinal static stability margin. The drag polar of the airplane is determine for cruising regime of flight, that means the regime of following an airliner.