Traditionally in CDMA system, selective rake receiver is the popular method of detection. When used in DS-UWB system, the complex in door environment will increase the channel paths. As the channel paths increase, the more fingers which are part of Rake receiver will increase. It will be difficult for hardware implement when consider the operation of channel estimation and Rake receiver. And it is unfavorable for hardware design. In this thesis, we will use partial Rake receiver to replace selective Rake receiver. Channel estimation is implemented by template the receiver signals within 2 bit time window length. The performance is acceptable and the hardware complexity is reduced. When implement the channel estimation, we combine some blocks of acquisition and channel estimation for reducing hardware complexity.

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This thesis deals with modelling of project teams and their behavior using the principles of system dynamics. Main goal of this thesis is to create a model using system dynamics, which will allow to simulate how projects are finished. Results from the model are going to be used to define the best possible strategy to finish a project in required time. Theoretical part of this work is composed of presentation of project management and further the thesis extensively describes system dynamics, principles of system dynamics, used diagrams and possible ways of application of system dynamics in the real world. Furthermore are described the principles and advantages of using models and specifically system dynamics models. In the practical part of this thesis is presented the created model, which allows for simulating of project team behavior based on the input from the user of the model. Model serves the purpose of finding the best possible strategy to finish the product successfully.

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Squeeze Film Dampers (SFD) provide viscous damping in rotor bearing systems to reduce lateral vibration amplitudes and to isolate mechanical components. Aircraft engine shafts, often supported on roller bearings, operate at high rotational speeds and are susceptible to large amplitude shaft whirl due to rotor imbalance. SFDs aid to reduce such large whirl amplitudes while also eliminating rotor instabilities. he current work quantifies experimentally the forced performance of two parallel squeeze SFDs separated by a central groove. Force coefficients are identified in a specialized SFD test rig constructed to undergo similar operating and loading conditions as in jet engines. Of interest is to quantify the effect of a central feed groove on the forced performance of SFDs and to validate predictions from a computational tool. The test rig comprises of an elastically supported bearing structure and one of two journals. Tests are conducted on two open ends SFDs, both with diameter D and nominal radial clearance c; each damper with two parallel film land lengths L= 1/5 D and 2L, separated by a feed groove of width L and depth 3/4 L. ISO VG 2 grade lubricant oil flows into the central groove via 3 orifices, 120 degrees apart, and then through the film lands to finally exit to ambient. In operation, a static loader pulls the bearing to various static off center positions with respect to the stationary journal, and electromagnetic shakers (2,200 N) excite the test system with single frequency loads over a frequency range to generate rectilinear, circular and elliptical orbits with specified motion amplitudes. A frequency domain method identifies the SFD mechanical parameters, viz., stiffness, damping, and added mass coefficients. The long damper generates 7 times more direct damping and 2 times more added mass compared to the short length damper. The damping coefficients are sensitive to the static eccentricity (up to 50 percent c) while showing lesser dependency on the amplitude of whirl motion (up to 20 percent c). On the other hand, added mass coefficients are nearly constant with static eccentricity and decrease with higher amplitudes of motion. The magnitudes of identified cross-coupled coefficients are insignificant for all imposed operating conditions for either damper. Large dynamic pressures recorded in the central groove demonstrate the groove does not isolate the film lands by merely acting as a source of lubricant, but contributes to the generation of large added mass coefficients. The recorded dynamic pressures in the film lands and central groove do not evidence lubricant vapor or gas cavitation for the tested static eccentricities and amplitudes of motion. The direct damping coefficients for both dampers are independent of excitation frequency over the frequency range of the tests. Predictions derived from a novel SFD computational tool that includes flow interactions in the central groove and oil supply orifices agree well with the experimental force coefficients for both dampers. The current work advances the state of the art in SFDs for jet engines.