The technique of synthetic aperture imaging is well applied in radar to produce images with high along-track resolution. However, when applied in sonar imaging, maintaining phase coherence across the length of the synthetic aperture had proven to be the greatest challenge due to the relatively much slower speed of sound waves and the instability inherent in an underwater towed platform. This work aims to study, analytically and experimentally, the potential of reconstructing synthetic aperture images, by the exact reconstruction algorithm in the time-domain, without the use of phase information. The absence of phase information results in images with a relatively lower along-track resolution. However, the benefits of hardware simplicity and higher mapping rate, not present with the use of side-scan sonar, are still enjoyed. In addition, greater flexibility and robustness is achieved as compared to a coherent synthetic aperture system. This is manifested in its resilience to path deviations, tolerance to sparse arrangement of elements in the aperture, and consequently higher achievable mapping rate. Software simulations were performed to study the impact of key parameters on the performance of an incoherent synthetic aperture system. Concepts such as the point-target energy response and signal to self-noise ratio were formed, which led to the formulation of design methodologies and tools for such a system. A novel algorithm is introduced to address the problems of false targets and long processing time. A new bulk motion compensation method is presented for situations where large path deviations cause severe image degradation and compensation is necessary. This technique, together with the algorithms developed in this work, was implemented with data from a sea-survey of the Aeolian Sky wreck. Results gave a positive indication of the theoretical frameworks established. This technique was then extended to achieve 3-D imaging capability. Results from laboratory tank trials that were carried out were encouraging, and led to the development of an original concept of incoherent synthetic aperture synthesis that is practical, robust, economical, and has 3-D imaging capability.

The aircraft fuel control system makes sure an engine has the precise amount of fuel required to generate power and thrust for every stage of flight. It therefore plays a role in determining the economics of flight. In order to maintain the economic equilibrium of performance and flight safety, it undergoes a Maintenance Repair or Overhaul (MRO) service after several hours of operation. A critical aspect of the MRO service is the test performed to validate the airworthiness of a fuel control system before it returns to service. The test of aircraft fuel control systems is human-centric by design. The operator uses a network of test systems to generate in-flight conditions similar to what the Unit-Under-Test (UUT) experiences on-board an aircraft engine, then performs tests to validate and verify its airworthiness. Thereafter, test results are recorded for regulatory compliance reasons after each test is performed successfully. An analysis of the test specification for the UUT involved in this study revealed 90% of an operator’s touch-time is automatable. The functions of control, data processing, data entry and supervision must be achieved automatically if they are to be performed autonomously by a cyber-physical test system. But the automation of these activities at the micro level does not guarantee their autonomous execution at a macro level by such a cyber-physical system composed of the network of test systems. Therefore, knowledge of a multidisciplinary array of fundamental concepts and how they can be fused to execute the test of aircraft fuel control systems autonomously, have been developed as presented in this thesis. For the function of process control, the response of the processes used to set test conditions is ~ 50Hz, five times the rate of process responses reported in typical process industries where automation of process control have been achieved. As a result of this fundamental knowledge, the design of the architectures for the functions of control and data processing is an asynchronous one. Noting that none of the data is fed back through a network like the case of Networked Control Systems or Supervisory Control and Data Acquisition Systems. The realization of the control functions for each process used to set test conditions is based on control laws synthesized through modelling of their respective actuation mechanisms. Of the three models developed, a 2nd order model has been identified as been representative of the dynamic and steady-state characteristics of each actuation mechanism. A typical actuation mechanism contains a high number of masses and springs whose physical modelling resulted in a model of 12th order. This model is highly unrepresentative of the transient and steady-state response observed in the process due to difficulty in estimating the internal parameters of respective actuators. A linear model synthesized from the calibration data of each actuation mechanism has also been investigated and found to be too ideal. Its response is unrepresentative of the dynamic characteristics of the actuation mechanisms. The processes used to generate test conditions have been set simultaneously using a network of PID controllers. The controllers’ gains are an order of ten less than what they were for the sequential set up of test conditions due the fact that there are interactions between the processes inside a UUT. Fundamentally however, this Thesis demonstrates an asynchronous architecture for the control function, which enables a pseudo steady-state execution of tests. In-practice, this has the potential to reduce the time it takes to perform a test by one-third. The function of supervision has been developed in the form of a Fault Detection Isolation and Recovery capability within the cyber-physical test system. The architecture for this function is designed based on minimalizing the constraint of the period of recoverability (PoR), where the deviations from normal operation need to be detected, the outcomes they could result to—diagnosed and recovery strategies executed to prevent test systems or the UUT deviate from normal operation, using measurements acquired in a time < PoR. Oscillations and offsets have been identified as the major causes of deviations in subsystems during the test of the aircraft fuel control system in this study. In order to diagnose a deviation, a fuzzy inference engine has been developed over a Fault Tree Analysis approach because it makes the automation of domain knowledge needed to realize the supervision function effective. Nevertheless, the contributions of this thesis are the knowledge gaps it uncovers and the formalized approaches it proposes in the form of architectures to plug these gaps. It provides a direction on how to actualize not only the concept of automation, but the realization of a cyber-physical system to test an aircraft fuel control systems. It is the architecture of a singular system capable of executing the functions performed by an operator autonomously, and surpassing what can be achieved in the case of simultaneous process control, automated detection and isolation of a critical deviations under the period of recoverability, that is the fundamental contribution of this thesis. So that in the not so distant future the test of aircraft fuel control systems can be performed by machines.

Nous analysons la coordination des firmes au sein de la filière de production du zinc métallique. Nousidentifions cinq critères déterminant le comportement de production des firmes. Une variable de coordinationest nécessaire pour trouver un équilibre entre ces cinq critères. Cette variable de coordination est la TreatmentCharge (TC) qui correspond à une déduction du prix du minerai au titre des frais de transformation en métal.Nous proposons deux hypothèses quant à la nature de la TC : variable de prix et variable technique d’équilibrede la filière. Nous concluons que sur le long terme la TC a un comportement proche d’un prix. Cependant, àcourt et moyen terme elle se rapproche d’une variable de coordination technique garantissant les débouchés, lesapprovisionnements et un revenu minimum aux firmes. Nous concluons que la TC est un indicateur avancé dela stabilité de la filière : l’évolution de celle-ci témoignerait du changement de l’organisation de la filière. Lafilière est stable lorsque la TC évolue au sein de bandes de fluctuation, dans la logique d’un « serpent dans letunnel » : sortie de ces limites, la TC indique une instabilité voire une dissolution probable de la coordination.Nous anticipons une évolution de la TC vers plus de flexibilité du fait des clivages grandissants entre ancienset nouveaux acteurs de la filière. Nous nous prononçons pour cette évolution du fait de la complexification dela filière qui la rend nécessaire, notamment du développement des contrats de court terme. Nous identifionscependant un risque pour les approvisionnements en zinc si la TC venait à disparaitre complètement. Noussuggérons que le maintien de la nécessaire coordination de la filière passe par un partage des investissementsdans une logique similaire au partage des profits afin de surmonter les défis posés par l’environnement productif. / We analyse firms coordination within the zinc metal production industry. We first identify 5 criteriadetermining the production pattern of the firms. We stress how a coordination variable is needed to strikea balance between these constraints, this variable being the Treatment Charge (TC). The TC is a deductionfrom the price of zinc metal to pay for its transformation from concentrate to metal. We offer two hypotheseson the nature of the TC: either a standard price variable, or a coordination variable based ont he technicalequilibrium of the industry. We conclude that the TC behaves as a price in the long run, but very much likea coordination tool in the short run. It also plays a role in distributing profits between firms, hence grantingstability to the balance of market power in the industry. Therefore, the TC is an advanced warming indicatorfor the stability of the market organisation of the zinc industry. The industry organisation is stable when theTC fluctuates within the limits of values (like a "snake in the tunnel"). If the TC hits one of the limits, thebalance is offset and the industry moves towards competition. We expect such an evolution in the mediumterm, with the TC becoming more flexible as a result. Nonetheless, should the TC be scraped altogether andreplaced by a market price, the stability of the industry supply chain might be at risk. We conclude with someadvice for the industry, sketching a first best scenario where firms of the industry would not only share profitsbut also investment plans. This would be the best way to resist the external pressures currently threatening totear out the industry to reorganise it for the sole purpose of short-run financial gains.

A possible way to continuously monitor the whole water distribution system is to equip pipes with many microsensors. If these sensors are to be integrated within the pipe walls, it is important to assess their impact on the structural integrity of the pipes. In order to test a large number of samples, small polyethylene samples were produced using compression moulding and tested in different stress modes such as tension, bending, Charpy impact and flexural creep, with respect to different chip sizes (4 and 16mm\(^²\)), shapes (circle and square), numbers (one and two), orientations and position as well as sample dimensions and chip-polyethylene interface. It was discovered that the square chip contributes to the highest increase in the polymer stiffness, but significantly reduces its ductility. The 4mm\(^²\) circle causes the smallest disruption in the polymer integrity, especially when including multiple chips and when there is no adhesion. It significantly improves the impact resistance, while its effect in the short and long term bending stress modes is insignificant. The 16mm\(^²\) circle perpendicular to the load direction failed in bending at large strains. The optimal chip orientation for improving the impact strength and reducing the embrittlement effect in tension is parallel to the applied load.

This thesis investigates the incorporation of target phase into sonar signal processing, for enhanced information in the context of acoustical oceanography. A sonar system phase calibration method, which includes both the amplitude and phase response is proposed. The technique is an extension of the widespread standard-target sonar calibration method, based on the use of metallic spheres as standard targets. Frequency domain data processing is used, with target phase measured as a phase angle difference between two frequency components. This approach minimizes the impact of range uncertainties in the calibration process. Calibration accuracy is examined by comparison to theoretical full-wave modal solutions. The system complex response is obtained for an operating frequency of 50 to 150 kHz, and sources of ambiguity are examined. The calibrated broadband sonar system is then used to study the complex scattering of objects important for the modelling of marine organism echoes, such as elastic spheres, fluid-filled shells, cylinders and prolate spheroids. Underlying echo formation mechanisms and their interaction are explored. Phase-sensitive sonar systems could be important for the acquisition of increased levels of information, crucial for the development of automated species identification. Studies of sonar system phase calibration and complex scattering from fundamental shapes are necessary in order to incorporate this type of fully-coherent processing into scientific acoustic instruments.

Dans ce travail de thèse, on s'est intéressé aux changement des propriétés électroniques en fonction du dopage de couches minces épitaxiées des composés supraconducteurs Bi2Sr2Can-1CunOy : phase Bi2Sr2CaCu2Oy (Tcmax=80 K) et Bi2Sr1.6La0.4CuOy (Tcmax=30 K) respectivement avec un et deux plans CuO2. Le changement des propriétés électroniques le plus étonnant se passe dans la région sous-dopée du diagramme de phase où un pseudogap s'ouvre à l'état normal dans le spectre des excitations électroniques. La mesure de la résistivité R(T), de l'effet Hall RH(T) et de la magnétorésistance MR(T,H) sur ces deux phases ayant le même réservoir de charges ont permis une étude directe de l'effet de pseudogap en fonction du nombre de plans CuO2 et de la température critique. Cet effet se manifeste par une déviation de R(T) par rapport à la loi linéaire se produisant au-dessous d'une température caractéristique T* et il est observé dans les deux phases. Toutes les courbes peuvent être superposées en fonction de T/T* sur une courbe unique, différente pour chaque phase, ce qui reflète une différence d'amplitude de l'effet de pseudogap dans R(T) d'un facteur 2, relié au nombre différent de plan CuO2. Par contre la température d'ouverture du pseudogap T* a le même ordre de grandeur dans les deux phases. Sa disparition rapide au voisinage de l'état optimal semble exclure une relation entre T* et Tc. De plus, l'existence d'un point critique au voisinage de l'état optimal est discutée ainsi que la corrélation possible entre les propriétés supraconductrices et les propriétés de l'état normal.

<p>Detta examensarbete är ett utvecklingsarbete av demonstrationsutrustning för enkel visning av fördelarna med M2M-tekniken vid insamling av mätdata och automatisk övervakning. Arbetet består av en praktisk del, som utgörs av demonstrationsväskan, och en mer teoretisk del, som utgörs av demonstrationsprogrammet. </p><p>Programmet har utvecklats till att med ett mätkort kopplat till en PC samla in mätvärden (spänningar), dessa skickas sedan som ett SMS med ett GSM-modem till en mottagare. Mottagaren kan vara en serviceman som vill ha felmeddelanden från utrustning inom dennes ansvarsområde, mottagaren kan även vara en server som rymmer en databas vilken används för att spara viktiga mätvärden för längre tid, t.ex. loggning av elförbrukning hos något kraftbolags kund. </p><p>Det hela har alltså resulterat i ett färdigt och väl fungerande program, som utför just det som är uppdraget ovan. Mätresultatenhar tillräcklig noggrannhet för detta uppdrag om att demonstrera fördelarna med M2M-tekniken, och mätresultatet kommer även fram till mottagaren i sin rätta form. </p><p>Detta betyder att M2M Communication AB nu kan demonstrera vinsten med M2M-tekniken för potentiell kund på ett enkelt och förklarande sätt. Integrerat i demonstrationsutrustningen har nu också företaget fått en enkel och självklar utrusning för att i praktiken se hur nya givare och annan utrusning fungerar ihop med ComHost 300 som är företagets primära produkt. </p> / <p>The goal with this master thesis is to develop a simple equipment to show the advantage of using M2M-technic when collect measured data and when using automatic monitoring of alarm and sensors. The thesis is divided in two parts, a practical part that corresponds to a case with sensors and equipment. The case is used to collect measure data to be used when demonstrating the theoretical part, which corresponds to the software program. The software program is developed to measure voltage with the data acquisition card, and then send them as a SMS text message via the GSM network. For this tasks the software also have to control the GSM-modem. This text message is either sent to a computer for logging in a database, or to the service department who owns the equipment measured. </p><p>This work has ended up in well function software that can be installed on a PC-system with a Windows 2000(tm) operation system. The accuracy on the measured data is good enough for the task to demonstrate the function of the M2M-technic. The text message is also arrive to the receiver as expected. </p><p>The result of this master thesis ends up giving the company M2M Communication AB the possibility to demonstrate the M2M-technic on a simple and explaining manner for a potential customer. Integrated in the new equipment the company also has been given a possibility to test new sensors and signal sources in a real world M2M test.</p>

In this study, numerical modeling of landslide generated tsunami waves in closed basins and their mechanisms are presented. Historical landslide generated tsunamis are investigated and also the governing parameters affecting impulse wave parameters are studied. The numerical model is based on the solution of nonlinear form of the long wave equations with respect to related initial and boundary conditions. In order to validate the outputs of the modeling by NAMIDANCE, empirical formulation is applied to the same cases as the numerical model and the results are discussed. The numerical model is then applied to Pervari Dam artificial reservoir as a case study to investigate the effects of potential landslide into the reservoir. The outputs of the numerical model are compared with empirical formulation results for different approaches of modeling the landslide effect in water body. The critical sections are observed for overtopping and maximum wave amplitude values and the results are discussed.

In Turkey with increasing energy demand by industrialization and urbanization, hydropower seemed to be the most environmental friendly and sustainable solution for the problem. However, hydropower has also environmental effects especially when hydropower projects are numerous on a single river, and they use almost entire water in the river. Environmental flow as a new term became popular in media with increased density of small hydropower projects in Turkey. It is the required flow in the part of diversion for Run-off River type of hydropower plant in order to protect health of the river / in other words, to balance components of the river, including physico-chemical quality standards, surface and groundwater, geomorphological dynamics, social, economic, cultural and landscape values. In this study, an analysis utilizing hydrological (desktop) environmental flow assessment methods is prepared for Turkey, focusing on the Pazarsuyu Basin as a case study, and the results are compared with the applications done by the Governmental Institutions. Moreover, insufficient applications with regard to environmental flow assessment are given and reasons for public concerns are pointed out due to small hydropower development in Turkey.

Waterhammer is an undesirable event, caused by sudden flow changes in a confined pipe system. When it occurs, its consequences can be very costly and even sometimes deadly. In general, it may be encountered in the penstocks of hydropower plants, water transmission lines, water networks, etc. Therefore, the operation guidelines of the hydropower plants should be defined correctly. In this thesis, waterhammer problems in pumped storage hydropower plants are investigated. Time dependent flow conditions in the penstocks are studied by the help of computer software, HAMMER. The software solves nonlinear differential equations by using method of characteristics. Firstly, hydraulic transients for various operational cases are investigated using some scenarios. Then a surge tank, protective device for waterhammer, is added to the system and for the same operational cases, hydraulic transients are studied again. Finally, the results obtained from the operation of the system with and without surge tank are compared. Wind-hydro hybrid systems are also included in the study.