In this thesis work, the implementations of the monopulse amplitude comparison and phase comparison DF algorithms are performed on an FPGA platform. After the mathematical formulation of the algorithms using maximum-likelihood approach is done, software simulations are carried out to validate and find the DF accuracies of the algorithms under various conditions. Then the algorithms are implemented on an FPGA platform by utilizing platform specific software tools. Block diagrams of the hardware implementations are given and explained in detail. Then simulations of hardware implementation of both algorithms are performed. Using the results of the simulations, DF accuracies under certain conditions are evaluated and compared to software simulations results.

In this thesis, the problem of Angle of Arrival estimation of radar signals with Time Difference of Arrival method in an outdoor land multipath environment with limited line of sight is analyzed. A system model is proposed. Effects of system, channel and radar parameters on the Angle of Arrival estimation performance are investigated through Monte Carlo simulations. Improving effect of utilization of diversity on the estimation performance is observed. Performances of the space diversity with noncoherent and selective combining are compared. Finally a realistic scenario is studied and performance of the proposed system is investigated.

In this thesis work, Cyclic Root MUSIC method is integrated with spatial smoothing and interpolation techniques to estimate the direction of arrivals of coherent,cyclostationary signals received via a Uniform Circular Array (UCA). Cyclic Root MUSIC and Conventional Root MUSIC algorithms are compared for various signal scenarios by computer simulations. A cyclostationary process is a random process with probabilistic parameters, such as the autocorrelation function, that vary periodically with time. Most of the man-made communication signals exhibit cyclostationarity due to the periodicity arising from their carrier frequencies, chip rates, baud rates, etc. Cyclic Root MUSIC algorithm exploits the cyclostationarity properties of signals to achieve signal selective direction of arrival estimation. Spatial smoothing is presented to overcome the coherent signals problem in a multipath propagation environment. Forward spatial smoothing and forward backward spatial smoothing techniques are investigated. Interpolation method is presented to cope with the restrictions of spatial smoothing on array structure. Although the array structure that is considered in this thesis (Uniform Circular Array), is not suitable for applying spatial smoothing directly, using interpolation method makes it possible. Performance of Cyclic Root MUSIC and Conventional Root MUSIC algorithms are compared under variation of various factors by computer simulations. Effects of signal type on the performance of the algorithms are observed by using different signal scenarios.

This thesis is composed of three main parts / displaying an analog composite video input by via converting to digital VGA format, license plate localization on a video image and image enhancement on FPGA. Analog composite video input, either PAL or NTSC is decoded on a video decoder board / then on FPGA, video data is converted from 4:2:2 YCbCr format to RGB. To display RGB data on the screen, line doubling de-interlacing algorithm is used since it is efficient considering computational complexity and timing. When taking timing efficiency into account, image enhancement is applied only to beneficial part of the image. In this thesis work, beneficial part of the image is considered as numbered plates. Before image enhancement process, the location of the plate on the image must be found. In order to find the location of plate, a successful method, edge finding is used. It is based on the idea that the plate is found on the rows, where the brightness variation is largest. Because of its fast execution, band-pass filtering with finite response (FIR) is used for highlighting the high contrast areas. Image enhancement with rank order filter method is chosen to remove the noise on the image. Median filter, a rank order filter, is designed and simulated. To improve image quality while reducing the process time, the filter is applied only to the part of the image where the plate is. Design and simulation is done using hardware design language VHDL. Implementations of the chosen approaches are done on MATLAB and Xilinx Virtex-2 Pro FPGA. Improvement of the implementation considering speed and area is evaluated.

An important step for the design of direction finding systems is the performance evaluation using numeric electromagnetic simulation tools. In this thesis, a method is presented for both modeling and simulation in a numeric electromagnetic simulation tool FEKO. The method relies on the data generated by FEKO. The data is then processed by correlative interferometer algorithm. This process is implemented in a MATLAB environment. Different types of antenna arrays including dipole, monopole and discone antennas are used. The antenna arrays are mounted on a UAV and SUV in order to see the platform effects. The direction finding performance is evaluated for different scenarios. It is shown that the presented approach is an effective tool for understanding the direction finding characteristic of antenna arrays.

Ground based radars often experience difficulties in target detection and direction finding (DF) applications due to the interference between the direct and surface reflected signals when the targets fly at low altitudes. In this thesis, the phenomena governing the low angle propagation are overviewed and a multipath signal model including the effects of refraction, specular reflection, diffuse reflection, curvature of the earth and antenna polarization is presented. Then, the model is utilized to develop detection and DF algorithms for the targets at low altitudes. The target detection algorithm aims to increase signal-to-noise ratio (SNR) to overcome the effects of signal fading caused by surface reflections. The algorithm is based on diversity combining and the combining weight vector is calculated by maximizing average value of SNR. The technique is compared with Maximum Ratio Combining (MRC) algorithm which is optimal in terms of SNR. In direction finding, it is the height of the target that is explored since the target range information is obtained from the time delay. The target height is estimated by utilizing Maximum Likelihood Estimation (MLE). The performance of our algorithm is compared with that of the technique that is known in the literature as Refined Maximum Likelihood (RML).

This study aims to test the effects of different way finding affordances on the usability of METU virtual campus built in Second Life virtual world in terms of users&rsquo / satisfaction, performance and mental workload. This study was conducted with 36 participants who are students at the Middle East Technical University. Participants were randomly put on of the five groups namely map, signboard, voice and agent groups and a control group. The participants were given navigational tasks in METU virtual campus within Second Life. In the experiment, the eye movements of the participants were examined with eye tracking tool in order to determine the areas which participants paid attention most. Also mental work load in their prefrontal cortex was examined with fNIR device. There was no significant difference among groups in terms of satisfaction, however / there were significant difference among groups in terms of task completion accuracy, time, length, navigation cue gaze duration and mental workload. Agent group has the highest accuracy score, map group has the highest time, length and navigation cue gaze duration score. Moreover, agent group has the highest mental workload but control group has the lowest mental workload. The results of the tests were used to provide guidance for the design of way finding affordances in METU virtual campus.

Sweden is getting an aging population and with this comes an increase in neurodegenerative diseases such as Alzheimer’s disease (AD). Bilingualism is also on the rise and this may result in an increase of bilingual people suffering from AD. Due to the linguistic deterioration associated with the illness people with AD, bilingual and monolingual, will be an increasing patient group with speech and language pathologists (SLPs). Word retrieval difficulty is an early symptom of the disease and several strategies to compensate for this have been observed (e.g. fillers, circumlocutions and semantic parafasias). The effectiveness of these strategies has not yet been established. With this background this study attempts to investigate which strategies are used by monolingual and bilingual people with AD to compensate for word retrieval difficulties. A case study was performed on four participants with AD, two of which were monolingual and two were bilingual. Spontaneous speech was collected by means of a semi-structured conversation and a short story was produced with picture support. The results showed that there were individual differences in terms of the compensatory strategies. The results indicated that the strategies’ effectiveness depended on the progression of the disease in each individual. No differences between the bilingual participants’ first and second language were observed with exception to the usage of code switching. The picture support seemed to be of some help for the participants to achieve better fluency of speech since word retrieval difficulties seemed to decrease. The conclusion is that SLPs could make their patients aware of several different strategies to compensate for word retrieval difficulties to discover what is the most effective for each individual; furthermore pictures can be used to help clients’ narratives. / Sverige får en allt äldre befolkning. Detta för med sig ökande antal personer med Alzheimers sjukdom (AD). Då sjukdomen innebär stor språklig påverkan kan denna patientgrupp förväntas öka inom den logopediska vården. Även andelen flerspråkiga i samhället växer, vilket gör att logopeder kommer att ta emot allt fler flerspråkiga äldre patienter. Ordmobiliseringssvårigheter har setts vara ett tidigt symtom vid sjukdomen både hos enspråkiga och flerspråkiga personer. Tidigare forskning har visat att ett flertal kompensatoriska strategier (t.ex. utfyllnader, omskrivningar och utbyten) används för att hantera dessa svårigheter men det är inte klarlagt hur väl dessa strategier fungerar. Därför undersöks i denna studie vilka kompensatoriska strategier som förekommer både hos enspråkiga och flerspråkiga personer med AD. En fallstudie genomfördes på fyra deltagare med AD, varav två enspråkiga och två flerspråkiga. Spontantal samlades in genom ett semistrukturerat samtal och en kortare berättelse genomfördes med hjälp av bildstöd. Resultaten visade att effektiviteten i de använda strategierna skiljer sig mellan individer. Hur långt deltagarna kommit i sjukdomsförloppet verkade dock ha betydelse. Ingen större skillnad mellan de flerspråkiga deltagarnas båda språk observerades förutom gällande användning av kodväxling. Deltagarna verkade i viss mån vara hjälpta av bildstöd för att uppnå bättre talflyt eftersom ordmobiliseringsproblematiken tycktes minska. Slutsatser som drogs är att logopeder kan medvetandegöra patienter och närstående om ett flertal olika strategier för att hitta den strategi som fungerar bäst för den individuella patienten samt att bildstöd kan användas för att underlätta berättande.

Automatinis testų rinkinių generavimas (pasaulyje priimtas angliškas sutrumpinimas – ATPG) yra pakankamai senai sprendžiama problema. Jos tikslas – surasti optimalų testinių vektorių sekas, kurios pilnai užtikrintų visas schemos gamybos etape padarytas klaidas per mažiausią laiką. Vienas iš skaitmeninių schemų testavimo ir testų rinkinių sudarymo metodas yra funkcinis testavimo metodas. Jo privalumai yra tame, kad testų rinkinių sudarymo programa nežino schemos vidinės struktūros, o testuoja tik idealų schemos modelį, kuri yra pateikta juodos dėžės pavidale, tai yra programa gali gauti idealaus schemos reakciją į tam tikrą įvedimo signalų vektorių. Šiame darbe parinktas funkcinis testavimo metodas. Šiame darbe aprašoma testinių rinkinių atrinkimo programinės įrangos teorinė bazė, automatinio testų rinkinio formavimo trumpa istorinė apžvalga, baltos ir juodos dėžės modelių pagristų formavimo algoritmų palyginimai. Aprašoma programų sistemos statinė struktūra bei jos komponentai, sistemos panaudojimo atvejai. Tyrimų dalyje aprašoma tyrimo metodika, siūlomi programos kokybės tobulinimo metodai. Eksperimentų dalyje aprašomi tyrimų eksperimentų rezultatai. / Automated test pattern generation (ATPG) problem is being solved for a relatively long time. Its' point is to find optimal test vector sequences, which would cover most of all production-caused digital circuit faults and would run for the minimum amount of time. One of the ways to test and generate test vectors for digital circuits is functional test method. Its' benefit is that system does not need to be aware of digital circuit's inner logical model, but has to deal only with the input, so that just the ideal model of the digital circuit can be used as a "black box". The program's algorithm can get ideal digital circuit's reaction for corresponding input test vector. This paper will mostly cover functional model approach to ATPG. This paper covers automated test vector generation software basic theory with brief historical review, comparison of white box and black box models' testing and test vector generation algorithms. Also the software's static structures along with its components, system’s typical use cases are covered. The research part of the paper is focused mostly on the algorithms used, containing research methods which provide the results for the experiment part.

<p>Since the 1980&rsquo / s, many dictatorships around the world have been replaced by new democracies. These old dictatorships were notorious for their human rights abuses. Many people were killed and tortured / and many others were disappeared. When the new governments came into power, they had to confront these injustices that were perpetrated under the predecessor regime. This was necessary to create a culture of human rights / promote a respect for the law and access to justice. Many confronted these injustices in different ways, some granted amnesty, some prosecuted and others instituted truth commissions. This research paper focuses on truth commissions. The research focuses particularly on the study of the South African Truth Commission. The mandate of the South African Truth Commission is analysed and the investigation into whether the commission served the purpose for which it had been established is discussed.</p>