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.

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.

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.

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.

This diploma thesis analyses the influence of the changes 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.

The design of the landing gear is one of the more fundamental aspects of aircraft design. The design and integration process encompasses numerous engineering disciplines, e.g., structure, weights, runway design, and economics, and has become extremely sophisticated in the last few decades. Although the design process is well-documented, no attempt has been made until now in the development of a design methodology that can be used within an automated environment. As a result, the process remains to be a key responsibility for the configuration designer and is largely experience-based and graphically-oriented. However, as industry and government try to incorporate multidisciplinary design optimization (MDO) methods in the conceptual design phase, the need for a more systematic procedure has become apparent. The development of an MDO-capable design methodology as described in this work is focused on providing conceptual designer with tools to help automate the disciplinary analyses, i.e., geometry, kinematics, flotation, and weight. Documented design procedures and analyses were examined to determine their applicability, and to ensure compliance with current practices and regulations. Using the latest information as obtained from industry during initial industry survey, the analyses were in terms modified and expanded to accommodate the design criteria associated with the advanced large subsonic transports. Algorithms were then developed based on the updated analysis procedures to be incorporated into existing MDO codes. / Master of Science

No description available.

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 chinchards. / National 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.

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.

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.