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Showing result 1 - 5 of 63 swedish dissertations matching the above criteria.
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1. Photonic devices with MQW active material and waveguide gratings : modelling and characterisation
Abstract : The research work presented in this thesis deals with modelling, design and characterisation of passive and active optical waveguide devices. The rst part of the thesis is related to algorithm development and numerical modelling of planar optical waveguides and gratings using the Method of Lines (MoL). READ MORE
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2. Active Control of Noise in Ventilation Systems : Analysis and Experiments
Abstract : In many kinds of buildings, the ventilation system constitute a well known source of broadband noise. Traditionally, duct born noise is attenuated using passive resistive silencers which produce a high level of attenuation over a broad frequency range. However, they tend to become large and bulky if designed for low frequency attenuation. READ MORE
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3. Time and Frequency Transfer using Passive Techniques in Active Fiber Optic Networks
Abstract : For the modern society, high precision time and frequency transfer have become crucial since a large number of systems, such as telecommunication systems, require precise and stable synchronization. Electric power companies use synchronized systems for taking stability measurements and searching for errors in their networks. READ MORE
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4. Reverberation Chamber Characterizations for Passive and Active OTA Measurements
Abstract : Reverberation chamber (RC) has drawn more and more attention as a multipath emulator over the past decade. It has been used for antenna efficiency measurements. It has also been used to measure diversity gain and multi-input multi-output (MIMO) capacity using multi-port antenna. READ MORE
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5. Measurements and Models of One-Way Transit Time in IP Routers
Abstract : The main goals of this thesis are towards an understanding of the delay process in best-effort Internet for both non-congested and congested networks. A novel measurement system is reported for delay measurements in IP routers, which follows specifications of the IETF RFC 2679. READ MORE