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11040 Uppsatser om Time estimation methods - Sida 1 av 736
Bestämning av osäkerheten hos skattningar av tyngdaccelerationen
In this master's thesis the problem of determining the uncertainty for an estimator of an unknown parameter is considered. The case we study is the estimation of gravity using a reversible pendulum. This involves the estimation of the point where two regression lines intersect. The estimated gravity is a function the coordinates of this point. One way to determine the uncertainty of this estimator is to use bootstrap methods.
Automatisk mätning och detektering av röjande signaler
This master thesis has been performed at Sectra Communications AB in Linköping where they manufacture electronic encryption devices. In cryptology it is essential that an eavesdropper cannot find the plain text. To assure that a system is safe, all devices are thoroughly examined so that they don?t emit any secret information, so called Compromising Emanations (CE). This is done by comparing the secret signal with measured signals on the screen of an oscilloscope, a process that is very time consuming and furthermore, the risk of missing compromising emanations is high.
Estimation of reindeer lichen biomass by image analysis
During consultation procedures between forest owners and the Sámi, data on, e.g., reindeer lichen biomass on the current site is needed. Hitherto, the existing methods of measuring lichen cover and biomass has been either objective methods such as the Point Intercept method, which is time consuming, or some sort of subjective visual estimation, which is faster but less accurate. However, both these methods are sensitive to different observers and/or to different inventories. This paper addresses the further development and evaluation of a photographical inventory method that uses colour distribution in images to estimate lichen biomass. During the autumn of 2011 six different locations, with different grazing pressure and lichen cover, in Norrbotten county were inventoried using both the Point Intercept method and the photographical method, complemented with collection of biomass samples.
Tillståndsskattning i robotmodell med accelerometrar
The purpose of this report is to evaluate different methods for identifying states in robot models. Both linear and non-linear filters exist among these methods and are compared to each other. Advantages, disadvantages and problems that can occur during tuning and running are presented. Additional measurements from accelerometers are added and their use with above mentioned methods for state estimation is evaluated. The evaluation of methods in this report is mainly based on simulations in Matlab, even though some experiments have been performed on laboratory equipment.The conclusion indicates that simple non-linear models with few states can be more accurately estimated with a Kalman filter than with an extended Kalman filter, as long as only linear measurements are used.
Segmentering och klassificering av LiDAR-data
With numerous applications in both military and civilian life, the demand for accurate 3D models of real world environments increases rapidly. Using an airborne laser scanner for the raw data acquisition and robust methods for data processing, the researchers at the Swedish Defence Research Agency (FOI) in Linköping hope to fully automate the modeling process.The work of this thesis has mainly been focused on three areas: ground estimation, image segmentation and classification. Procedures have in each of these areas been developed, leading to a new algorithm for ground estimation, a number of segmentation methods as well as a full comparison of various decision values for an object based classification. The ground estimation algorithm developed has yielded good results compared to the method based on active contours previously elaborated at FOI. The computational effort needed by the new method has been greatly reduced compared to the former, as performance, particularly in urban areas, has been improved.
Effektiv betong för småhusproduktion : Betong med högt luftinnehåll för platta på mark
This Masters thesis work describes a comparison between two different methods for estimation of the down channel (base station to mobile subscriber) in Wide-band Code Division Multiple Access (WCDMA). The first estimation method, Optimal Feed-forward Channel Estimation (OFCE), is a conventional method that bases the estimates on data that is known to both sender and receiver, so called pilots. The second method, Decision Directed Channel Estimation (DDCE), is an elaboration of OFCE. It also uses user data for estimation. Simulations show that DDCE, in comparison to OFCE, does not attain an improvement in signal-to-noise-ratio (SNR) for high bit error rates (BER).
Utvärdering av en beslutsåterkopplad kanalestimator för tredje generationens mobiltelefonisystem
This Masters thesis work describes a comparison between two different methods for estimation of the down channel (base station to mobile subscriber) in Wide-band Code Division Multiple Access (WCDMA). The first estimation method, Optimal Feed-forward Channel Estimation (OFCE), is a conventional method that bases the estimates on data that is known to both sender and receiver, so called pilots. The second method, Decision Directed Channel Estimation (DDCE), is an elaboration of OFCE. It also uses user data for estimation. Simulations show that DDCE, in comparison to OFCE, does not attain an improvement in signal-to-noise-ratio (SNR) for high bit error rates (BER).
Betongbjälklag med limmad matta : olika behandlingars effekt på alkalitet, fukthalt och emissionsbildning
This Masters thesis work describes a comparison between two different methods for estimation of the down channel (base station to mobile subscriber) in Wide-band Code Division Multiple Access (WCDMA). The first estimation method, Optimal Feed-forward Channel Estimation (OFCE), is a conventional method that bases the estimates on data that is known to both sender and receiver, so called pilots. The second method, Decision Directed Channel Estimation (DDCE), is an elaboration of OFCE. It also uses user data for estimation. Simulations show that DDCE, in comparison to OFCE, does not attain an improvement in signal-to-noise-ratio (SNR) for high bit error rates (BER).
Utvärdering av en beslutsåterkopplad kanalestimator för tredje generationens mobiltelefonisystem
This Masters thesis work describes a comparison between two different methods
for estimation of the down channel (base station to mobile subscriber) in
Wide-band Code Division Multiple Access (WCDMA).
The first estimation method, Optimal Feed-forward Channel Estimation (OFCE), is
a conventional method that bases the estimates on data that is known to both
sender and receiver, so called pilots. The second method, Decision Directed
Channel Estimation (DDCE), is an elaboration of OFCE. It also uses user data
for estimation.
Simulations show that DDCE, in comparison to OFCE, does not attain an
improvement in signal-to-noise-ratio (SNR) for high bit error rates (BER). An
improvement is only seen when the BER becomes much lower than what is common in
real situations.
In conclusion DDCE is complicated, involves many mathematical operations and
gives insignificant improvement of SNR when BER takes common values. It is
legitimate to question if it is possible to use the method in a real mobile
phone system..
Elevers värderingar av föräldramedverkan i grundskolan. : En enkätundersökning
AbstractParental participation is something that is included in school either we like it or not. Several studies have been done about this phenomena but not many of them have examined the pupils estimation about parental participation. Therefore did we get interested about the pupils situation because why haven?t almost anyone asked the pupils about this phenomena when it?s constructed fore them? To learn more about the pupils estimation did we a questionnaire in twelve different classes with children in the ages between 10-16 years. The results we got from the questionnaire concerning the pupils estimation about parental participation were both expected and unexpected.Keywords: Parental participationQuestionnairePupil estimation.
En indirekt metod för adaptiv reglering av en helikopter
When a helicopter is flying, the dynamics vary depending on, for example, speed and position. Hence, a time-invariant linear model cannot describe its properties under all flight conditions. It is therefore desirable to update the linear helicopter model continuously during the flight. In this thesis, two different recursive estimation methods are presented, LMS (Least Mean Square) and adaptation with a Kalman filter. The main purpose of the system estimation is to get a model which can be used for feedback control.
Realistisk restidsberäkning för comodal reseplanering
With increasing traffic congestion problems in bigger cities, it is becoming more and more important to provide the traveller with correct information about all transport alternatives. When doing that, the traveller gets the opportunity to make the best decision based on the current traffic situation. Instead of traditional travel planners, where public and private transport modes are presented separately, the co-modal travel planner offers a combination. In order to make the comparison correct and fair, the travel times have to be estimated realistically and on equal basis. This master thesis focuses on how to estimate travel times in the city of Stockholm for journeys by cars, public transport, bicycles and also for walking.An investigation of the available data on maps and travel times shows where the currently used methods are lacking.
Utveckling och implementering av ett audiopejlsystem baserat på tidsdifferensmätning
The use of spread spectrum signals has increased dramatically in military applications. Finding methods for detecting and positioning of these signals have become interesting research areas for signal intelligence purposes. One method is to measure the time difference of arrival (TDOA) that occurs when two receivers are synchronous and spatially separated. Based on the TDOA-technique an audio-demonstrator has been developed and implemented. This report describes the theory for how sound received in microphones can be used to extract information about the transmitter?s position from the measured time difference.
Sagostunder på folkbiblioteket: ur sagostundsledarens perspektiv.
This masters thesis takes the providers perspective on public library story times for children. The main questions are: What perspectives can the providers have? How does the perspective affect the content and how is the story time drawn up? Five story time providers were interviewed about the purpose of their story times, the methods they used and the content they chose. A model with four criteria was used to analyze the result of the interviews. The criteria were: adult criteria, consideration of the childrens view, pedagogical criteria and literary/story time criteria.
Effektiva Lagringsmetoder för Glesa Matriser
Sparse matrices are often used in numerical algorithms that solve linear equation systems. Many methods for storing sparse matrices have been proposed and implemented during the years. These methods focus primarily on minimizing the total memory consumption and the time that it takes to store a sparse matrix. This report researches the available storage methods for sparse unstructured matrices. The formats that are researched and implemented are COO, CRS and ELL.