The use of wireless technology in the process industry is becoming increasingly important to obtain fast deployment at low cost. However, poor channel quality often leads to retransmissions, which are governed by Automatic Repeat Request (ARQ) schemes. While ARQ is a simple and useful tool to alleviate packet errors, it has considerable disadvantages: retransmissions lead to an increase in energy expenditure and latency. The use of Forward Error Correction (FEC) however offers several advantages. We consider a Hybrid-ARQ-Adaptive-FEC scheme (HAF) based on BCH codes and Channel State Information. This scheme is evaluated on AWGN and fading channels. It is shown that HAF offers significantly improved performance both in terms of energy efficiency and latency, as compared to ARQ.

When patients move during an MRI examination, severe artifacts arise in the reconstructed image and motion correction is therefore often desired. An in-plane motion correction algorithm suitable for PRESTO-CAN, a new 3D functional MRI method where sampling of k-space is radial in kx-direction and kz-direction and Cartesian in ky-direction, was implemented in this thesis work. Rotation and translation movements can be estimated and corrected for sepa- rately since the magnitude of the data is only affected by the rotation. The data were sampled in a radial pattern and the rotation was estimated by finding the translation in angular direction using circular correlation. Correlation was also used when finding the translation in x-direction and z-direction. The motion correction algorithm was evaluated on computer simulated data, the motion was detected and corrected for, and this resulted in images with greatly reduced artifacts due to patient movements. / När patienter rör sig under en MRI-undersökning uppstår artefakter i den rekonstruerande bilden och därför är det önskvärt med rörelsekorrigering. En 2D- rörelsekorrigeringsalgoritm som är anpassad för PRESTO-CAN har tagits fram. PRESTO-CAN är en ny fMRI-metod för 3D där samplingen av k-rummet är radiell i (kx,kz)-planet och kartesisk i ky-riktningen. Rotations- och translationsrörelser kan estimeras separat då magnituden av signalen bara påverkas av rotationsrörelser. Eftersom data är samplat radiellt kan rotationen estimeras genom att hitta translationen i vinkelled med hjälp av cirkulär korrelation. Korrelation används även för att hitta translationen i i x- och z-riktningen. Test på simulerat data visar att rörelsekorrigeringsalgoritmen både detekterar och korrigerar för rörelser vilket leder till bilder med mycket mindre rörelseartefakter.

Redeye artifact is the most prevalent problem in the flash photography, especially using compact cameras with built-in flash, which bothers both amateur and professional photographers. Hence, removing the affected redeye pixels has become an important skill. This thesis work presents a completely automatic approach for the purpose of redeye detection and removal and it consists of two modules: detection and correction of the redeye pixels in an individual eye, detection of two red eyes in an individual face.This approach is considered as a combination of some of the previous attempts in the area of redeye removal together with some minor and major modifications and novel ideas. The detection procedure is based on the redness histogram analysis followed by two adaptive methods, general and specific approaches, in order to find a threshold point. The correction procedure is a four step algorithm which does not solely rely on the detected redeye pixels. It also applies some more pixel checking, such as enlarging the search area and neighborhood checking, to improve the reliability of the whole procedure by reducing the image degradation risk. The second module is based on a skin-likelihood detection algorithm. A completely novel approach which is utilizing the Golden Ratio in order to segment the face area into some specific regions is implemented in the second module. The proposed method in this thesis work is applied on more than 40 sample images; by considering some requirements and constrains, the achieved results are satisfactory.

Consider a time series model which is stationary apart from a single shift in mean. If the time of a level shift is known, the least squares estimator of the magnitude of this level shift is a minimum variance unbiased estimator. If the time is unknown, however, this estimator is biased. Here, we first carry out extensive simulation studies to determine the relationship between the bias and three parameters of our time series model: the true magnitude of the level shift, the true time point and the autocorrelation of adjacent observations. Thereafter, we use two generalized additive models to generalize the simulation results. Finally, we examine to what extent the bias can be reduced by multiplying the least squares estimator with a shrinkage factor. Our results showed that the bias of the estimated magnitude of the level shift can be reduced when the level shift does not occur close to the beginning or end of the time series. However, it was not possible to simultaneously reduce the bias for all possible time points and magnitudes of the level shift.

This thesis describes a numerical modelling methodology to interpret dynamic fluctuations in pore-pressures to isolate the effects of loading associated with changes in total soil moisture (site water balance) alone. The methodology is required to enhance the data-interpretation and performance-assessment for potential applications of a novel piezometer-based, large-scale, geological weighing lysimeter. This interpretative methodology is based on a method of superimposing computer-based numerical analyses of independent causes of pore-pressure transients to separate the different pore-pressure responses. Finite element coupled load-deformation and seepage numerical models were used to simulate field-observed piezometric responses to water table fluctuations and loading induced by surface water balance (using meteorological data).<p> Transient pore-pressures in a deep clay-till-aquitard arising from variations in the water table within a surface-aquifer were modelled and removed from the measured pore-pressure record (corrected for earth tide and barometric effects) to isolate and identify pore-pressure fluctuations arising from loading associated with site water balance. These estimates were compared to simulated pore-pressure responses to an independently measured water balance using meteorological instrumentation. The simulations and observations of the pore-pressure responses to surface water balance were in good agreement over the dry years of a 9-year period. Some periods of significant differences did occur during wet years in which runoff, which is not accounted for in the current analyses, may have occurred.<p> The identification of pore-pressure response to total soil moisture loading using the developed numerical modelling methodology enhances the potential for the deployment of the piezometer-based geological weighing lysimeter for different applications which include real-time monitoring of site water balance and hydrological events such as precipitation and flooding. Interestingly, the disparity occurring during the wet years even suggests the potential to adapt the method to monitor runoff (net lateral flow).<p> The methodology also demonstrated the capability to accurately estimate in situ elastic and hydraulic parameters. Calibration of the model yielded equivalent properties of the aquitard (hydraulic conductivity, Kv, of 2.1E-5 m/day and specific storage, Ss, of 1.36E-5 /m) for a Skemptons B-bar coefficient of 0.91 for an assumed porosity of 0.26. Sensitivity tests also provided insight into the consolidation and pressure propagation (swelling) behaviour of the aquitard under parametric variations. The parameters obtained are consistent with range of values reported for glacial clay till soil. Therefore, this work also provides a unique case history of a method for determining, large scale, in situ material properties for geo-engineers and scientists to explore by simply using piezometric and meteorological data.

This study discusses the monetary policy transmission mechanism in the different channels. The analysis is conducted using generalized impulse response functions derived from a factor-augmented vector error correction (FAVECM) model. The FAVECM methodology as developed by Lee (2009) extends the factoraugmented vector autoregression (FAVAR) model to analyze long-run and shortrun dynamics of non-stationary variables. This recenly derived FAVECM model combines the advantages of factor model and the VECM model. The estimations are conducted using 174 macroeconomic time series in monthly frequency for the period January 2000 to September 2009. Results indicate that interbank call loan rate, deposit rate and prime lending rate are conintegrated, which provides sufficient evidence of the existence of the credit channel in monetary transmission system. Other GIRF results are generally consistent of the expected monetary policy effectiveness.

This study revists Purchasing Power Parity (PPP) and discusses the monetary policy transmission mechanism in exchange rate channels. The analysis is conducted using generalized impulse response functions derived from a Factor- Augmented Vector Error Correction (FAVECM) model. The FAVECM methodology as developed by Lee (2009) extends the Factor- Augmented Vector Autoregression (FAVAR) model to analyze long-run and shortrun dynamics of non-stationary variables. This recently derived FAVECM model combines the advantages of factor model and the VECM model. The estimations are conducted using 157 macroeconomic time series in monthly frequency for the period January 2000 to September 2009. Results indicate that PPP exists and expansionary devaluation effect in Taiwan. Other GIRF results are generally consistent of the expected exchange rate effectiveness.

As the two main components of household portfolios, stocks and real estate are likely to catch people¡¦s attention. Although the number of extant studies on the interaction between the stock and real estate markets is large, the views and empirical evidence in those studies show inconsistent results. This dissertation provides an explanation for the inconsistent results: market imperfection. Employing the threshold vector error correction model to examine the interaction between Taiwan¡¦s stock and real estate markets during the period from 1973Q2 to 2009Q4, the empirical results support this explanation. When the transaction benefit from the disequilibrium between the stock and real estate markets can cover the potential cost resulting from market imperfection, the relationship between the stock and real estate markets is integrated; but when there is slight disequilibrium, the price of real estate will not converge since the arbitrage benefit cannot cover the cost of transaction. As a result, the relationship is segmented. The empirical results of the study are very robust as similar conclusions result when different proxies for housing prices are used. The interactions between the stock and the sub-region housing markets also show similar results. Finally, when macroeconomic factors are considered, the asymmetric dynamic relationship is still significant.

This study explores the dynamics between stock price and exchange rates through the cointegration methodology proposed by Herwartz and Luetkepohl (2011). Moreover, it consider the vector error correction model (VECM) with conditional heteroscedastic variance. And we use a feasible generalized least squares (FGLS) estimator to estimate the cointegrating vector. This paper analysis some Asian countries' data from 1997 to 2010. The evidence result suggests that Malaysia and Singapor's stock price and exchange rate are positively related. But Hong Kong's stock price is negatively related to exchange rate.

This study aims to design a Shunt Semi-Active Power Factor Correction Circuits , which can be applied to high power circuit by low switching frequency. The designed circuit can avoid power loss working with high switching frequency when using the method of active power factor correction .The experimental configuration based on DSP is applied to a compressor of air conditioner with varied load. The simulation check the developed circuit using Ispice . Both of the experimental and simulation results have guaranteed the derived configuration reach the expected goals.