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585 Uppsatser om Signal transmission - Sida 18 av 39
Analys och förbättringsförslag för riktkopplardesign
Ericsson develops a new stripline directional coupler. Its design is described in appendix B and differs from the directional couplers Ericsson uses in current products. The new directional coupler will be used for transmission power measurement in future UMTS 3G base stations.The most important parts of directional coupler theory are presented. It is necessary to study this theory to understand how the coupler works and how it should be designed to get good performance.Optimal directional coupler termination component values to get high directivity and broad directivity bandwidth have been investigated.The trim screws trim ranges have been studied.A simple analysis of serial production performance when termination component tolerances are taken into consideration has been done.The resistance components reactive (inductive/capacitive) characteristics at 2.14 GHz have been analyzed.The directivity performance limitations of the directional coupler, when Ericsson?s band pass filter is connected, are investigated.Design changes leading to better performance are proposed.
Signalanalys med ATLAS
On Ericsson Ltd in Borås a wireless communication system called MINI-LINK? is produced. In order to sell their product with the best possible quality guaranty, there is a signal processing circuit called ATLAS implemented in the system. This circuit would eventually be useful in the production and for the repairs of the radio units. Our commission was to examine the possibility for this use.
Windbelt
Radio Frequency Identification, RFID, is a convenient way to enable contactless identification which does not require any physical nor optical contact. As with any radio-based communication the signal can be intercepted, thus making the technology vulnerable to several kinds of attacks. Interception of communication is not the only threat. Since RFID tags might contain personal information or information that will grant the owner access to secure areas, skimming and spoofing attacks are also major threats against this technology. In this thesis report, the perspective of an adversary is portrayed in an RFID-enabled environment by presenting where RFID is used and how it could be abused.
Optical and Structural Properties of CuxS Quantum Dots Concerning H2O/Ethanol Solvent Ratio
Nanotechnology, one of the most interesting sciences today will no doubt have an enourmous impact on tomorrow's society and industry. One of the most interesting nanomaterial that has been discovered is the semiconductor quantum dot (QD). This material shows interesting novel properties such as a size-dependent band gap, which is an effect caused by the quantum confinement effect in all three dimensions. Due to this phenomenon the absorption spectrum can be tuned to the desired value by adjusting the size of the QD.This thesis aims to investigate how the solvent ratio of H2O/Ethanol affects the optical and structural properties of copper sulfide QDs manufactured in a chemical synthesis way using modern microwave heating. The process of manufacturing QDs using chemical synthesis often involve a capping-agent to prevent the QDs from agglomerate into bigger structures.
Analys av säkerheten av RFID i inpasseringssystem
Radio Frequency Identification, RFID, is a convenient way to enable contactless identification which does not require any physical nor optical contact. As with any radio-based communication the signal can be intercepted, thus making the technology vulnerable to several kinds of attacks. Interception of communication is not the only threat. Since RFID tags might contain personal information or information that will grant the owner access to secure areas, skimming and spoofing attacks are also major threats against this technology. In this thesis report, the perspective of an adversary is portrayed in an RFID-enabled environment by presenting where RFID is used and how it could be abused.
Passive acoustic diver detection
This report discusses a method to detect divers in harbour environments usingpassive acoustic detection. The goal was to achieve as high detection as possiblewithout having too high false alarm rate. A short execution time was also desirable.By using the characteristic of an inhalation a band-pass filter was applied to the signalto improve the signal to noise ratio. After the filtering an energy estimation of thesignal was made. This energy estimation was later used in a frequency analysis, whichcould tell us if there were enough energy in the frequencies that correspond to adivers breathing frequency.
Testprogram till hårdvara på en viktindikator
Radio Frequency Identification, RFID, is a convenient way to enable contactless identification which does not require any physical nor optical contact. As with any radio-based communication the signal can be intercepted, thus making the technology vulnerable to several kinds of attacks. Interception of communication is not the only threat. Since RFID tags might contain personal information or information that will grant the owner access to secure areas, skimming and spoofing attacks are also major threats against this technology. In this thesis report, the perspective of an adversary is portrayed in an RFID-enabled environment by presenting where RFID is used and how it could be abused.
Adaptiv temperaturreglering av bostadshus
The control of indoor temperature must be able to handle large time constants and both measureable disturbances like outdoor temperature, and non-measurable disturbances, like waste heat from appliances. Due to cheaper microcontrollers (small computers with designated tasks) with better performance, more advanced and computation-demanding methods for control can be used.In this thesis, Generalized Predictive Control (GPC) has been implemented and tested on a theoretically derived model of a house. GPC states that a model of the system is estimated in every sample, and the control is carried out simultaneously, based on predictions of the model. Disturbances like solar radiation can be estimated and used in the control as well. The control signals are determined by quadratic programming, which makes it possible to consider conditions, for example limitations on the control signals.GPC requires a number of parameters to be defined, like model order and control signal penalty, but is relatively robust for variations in them.
Dynamisk modellering av VSC-HVDC : En statisk och dynamisk modelldesign o?ver VSC-HVDC fo?r implementering i ARISTO
This thesis treats the subject of a complete steady state and dynamic model of the VSC-HVDC covering both the AC and DC system-side of the converter. The topology of the model is recreated after the scheduled transmission line in the south of Sweden, called SydVa?stla?nken. The topology covers both a simple two terminal connection as well as a multi-terminal one. This model is to be implemented in the power system simulation program ARISTO.
Inlösen eller extrautdelning?: En studie av sambandet mellan valet av kapitalåterföringsmetod och värdeskapande för aktieägarna
This thesis studies the stock price reaction around 68 announcements of special dividends and share redemptions on the Swedish stock market between the years of 2003 and 2007. We show that for the Swedish private investor, the tax effect of a share redemption is lower than that of a special dividend. Moreover, a share redemption could be interpreted as a signal of undervaluation. These two factors lead us to assume that the stock market would react more positively in connection to the announcement of a share redemption. We test this hypothesis through an analysis of the risk-adjusted abnormal return for the observations in the sample.
Image follows structure
Background: The business market today is characterized by tough competition amongst the competitors to capture consumers? interest and money. One marketing tool companies can use to achieve this is the company?s image. The customer buys not only a product, but also the image that the company or the product is associated with.
Priming av självrelevanta ord : Kan attributionsstil påverkas av omedvetna signaler?
Människor tenderar att attribuera framgångar till sig själva och misslyckanden till externa källor, fenomenet kallas för Self-serving bias. Hur individer attribuerar kan enligt forskning påverkas av bland annat graden av självkontroll samt självkänsla. Enligt forskning kan intentioner eller beteendemål aktiveras automatiskt och omedvetet av en utlösande signal, så kallad priming, och därmed aktivt guida en persons självreglering. Denna studie har genom ett experiment, med 56 högskolestudenter, undersökt om priming av självkontroll och självförtroende kan påverka hur en individ attribuerar vid framgång och misslyckande. Resultatet visade ingen signifikant skillnad mellan priminggrupperna.
Diagnosis and molecular epidemiology of bovine rotavirus and coronarvirus in Brazil
Rotavirus and coronavirus are the two most common viral causes of neonatal calf diarrhea and their presence causes a lot of economic damage to the farmers as well as suffering to the animal. By getting better knowledge about the viruses we may help in tracing transmission and in producing new vaccines. This paper served to study the molecular epidemiology of rotavirus and coronavirus in fecal samples collected from two different farms in the state of São Paulo, Brazil. These samples have been studied with focus on the gene VP4, VP7, NSP4 in rotavirus and the gene S1 in coronavirus. From the first farm the screening PCR showed that 12/48 samples were positive for rotavirus and 4/48 positive for coronavirus.
Mjukvaruverktyg för loggning och analys avindustriella processer
This report discusses developing a software log tool for analysis of industrial processes. The target was to develop software that can help electro Engineers for monitor and fault finding in industrial processes. The tool is called PLS (Process log server), and is developed in Visual Studio.NET Framework 2005. PLS works as a client with Beijer Electronics OPC Server. The program is able to read data from PLC (Programmable Logic Controller), trough the OPC Server.
Automatisk nivåreglering av strålkastare
To be allowed to sell Z-suspended vehicles with dipped beam Xenon or LED lighting, Scania have to develop automatic headlight level control. This master?s thesis aims to be the foundation to that development.The thesis consists of several parts; a market analysis of how competitors to Scania and the general vehicle industry solve this problem; several available principles for detecting the amount of control needed; the construction of a test station for sensors, a control unit and components connected controlled by the control unit; a further theoretical and practical development of one principle ? one rotational sensor connected between the chassis and the back drive axis; a state flow model programmed in Simulink that produces the control signal for the headlight leveling from the sensor input.Lastly the thesis gives some recommendations to the further development and implementation of automatic headlight level control on Scania vehicles..