An Intelligent Algorithm for the Process Section of Radar Surveillance Systems

In this thesis, we cope with the fundamental mathematical and physical problems of the space-time-Doppler UWB system design for fading channels: multi-input multi-output (MIMO) wireless communication with adaptive filtering. The estimation algorithm from equalizer providing an accurate parameters estimate is investigated. UWB radio is a fast emerging technology with uniquely attractively features inviting major advances in wireless communications, networking, radar, imaging, and positioning systems. By its rule-making proposal in 2002, the Federal Communications Commission (FCC) in the United States essentially unleashed huge new bandwidth (3.6-10.6 GHz) at the noise floor, where UWB radios overlaying coexistence RF systems cerate using low-power ultra-short information bearing pulses. Right now, there are three basic types of UWB: multiband OFDM UWB (MB-OFDM UWB), impulse-UWB (I-UWB), and direct sequence UWB (DS-UWB). We focus on I-UWB and MB-OFDM-UWB, and compare their performance. A simple means for spreading the spectrum of low duty cycle pulse trains is time hopping (TH), with pulse position modulation (PPM) for data modulation at the rate of many pulses per data bit. The main contribution of this thesis for I-UWB is the design of leading edge detectors, coherent correlation detector (CCD), and pilot performance enhancement compared with different Rayleigh and Ricean fading conditions. For MB-OFDM UWB, we have considered the performance analysis and design criteria of MIMO OFDM UWB systems for high data-rate wireless transmission. The signal processing of frame detection, time synchronization, frequency synchronization, channel estimation, synchronization tracking using pilot subcarriers and 2-D MIMO detection algorithms is discussed. The main contributions of this thesis are 1) Compared with receiver employing the Maximum Likelihood (ML) detector, the receiver employing a low-complexity linear Minimum Mean Square Error (MMSE) demodulator can perform a limited performance loss in spatially uncorrelated channels. 2) Due to the operations of spreading and dispreading combined with MMSE-based frequency domain equalization, the adverse effects of the low-SNR subcarriers on the average BER performance are potentially improved. This is a direct consequence of spreading, because even if the signal corresponding to a specific chip is obliterated by a deep frequency domain channel fade, after dispreading these effects are spread over the Walsh-Hadamard Transform (WHT) length. Hence there is a high chance of still recovering all the partially affected subcarrier symbols without errors. 3) As a test case, the OFDM-based 200 Mb/s MB-UWB network (IEEE 802.15.3a) are considered, but the simulation results are shown above section. 4) The simulation channel can be easily applied to NOS and NLOS situation with WHT transformation from Simulink model. The fading channels of UWB with low/high signal to noise ratio (SNR), multipath effects, and multiuser interference may introduce large errors in location. The location engine performs the following tasks: █ Data fusion techniques: Different data fusion techniques are implemented using Time Of Arrival (TOA), Angle Of Arrival (AOA), or a combination of both. █ Channel modeling: A multipath, multiuser channel environment is created that models path loss, shadowing, Rayleigh fading, and Doppler frequency effects. █ Parameter estimation: TOA and AOA estimation algorithms are implemented as part of the location finding engine. Different variations of algorithms are implemented for performance and comparison purposes. █ Configuring the physical layer for different wireless networks. Among the programmable parameters are spreading factor, packet size, training length, constellation type, modulation technique, carrier frequency, level of transmitted signal power, and the number of antennas at the transmitter for both sides. █ Configuring the mobile user conditions. The wireless channel models depend on the Doppler frequencies present in the environment. The Doppler frequency depends on the mobile speed and carrier frequencies as input and generates a Rayleigh fading channel with the U-shape Doppler spectrum. █ Configuring the environmental parameters and network geographical structure. One of the factors affecting the performance of the wireless location system is the environment type (e.g., bad urban, urban, suburban, or rural area). For example, in a bad urban area with many blocking objects and buildings, non-line of sight (NLOS) effects plays an important role in the estimation accuracy.

Time-Scale Modification (TSM) is a well-researched field and allows for time-domain manipulation of a signal without modifying the pitch or timbre. Many TSM methods have been presented, however quantitative results on the quality of these methods are rare, with most methods reporting informal listening tests. This is likely due to the timecommitment and cost of subjective testing. Additionally, an objective measure of quality has not yet been developed that is suitable for timescaled signals. This dissertation describes the design of e ective objective measures of quality for TSM. TSM methods are, generally, single channel algorithms that give poor results when applied to multi-channel signals, as the phase relationship between channels must be maintained. This dissertation proposes a method and additional variant for maintaining the phase relationship between channels and retaining the presence in the centre of the stereo signal. The method involves pre- and post-processing the signal, with the variant processing each frame for real-time suitability. Sum and di erence transformations of the stereo signal are used for TSM and result in a large improvement in stereo phase coherence, consequently maintaining the stereo field. The proposed method produces a highquality stereo output and greatly improves quality over the independent channel processing method. It also allows for simple implementation around all existing TSM frameworks. A modification to the Epoch-Synchronous Overlap-Add (ESOLA) TSM algorithm is proposed in this dissertation. The proposed method, Fuzzy Epoch-Synchronous Overlap-Add, improves on the previous ESOLA method through cross-correlation of time-smeared epochs before overlap-adding. This reduces distortion and artefacts while the speaker's fundamental frequency is stable, as well as reducing artefacts during pitch modulation. The proposed method is tested against well-known TSM algorithms. It is preferred over ESOLA and gives similar performance to other TSM algorithms for voice signals. It is also shown that this algorithm can work effectively with solo instrument signals containing strong fundamental frequencies. No effective objective measure of quality for TSM exists. This dissertation details the creation, subjective evaluation and analysis of a dataset, for use in the development of an objective measure of quality for TSM. Comprising two parts, the training subset contains 88 source files processed using six TSM methods at 10 time-scales, while the testing subset contains 20 source files processed using three additional methods at four time-scales. The source material contains speech, solo harmonic and percussive instruments, sound effects and a range of music genres. 42,529 ratings were collected from 633 sessions using laboratory and remote collection methods. Analysis of results shows no correlation between age and quality of rating; equivalence between expert and non-expert listeners; negligible di erences between participants with and without hearing issues; and negligible di erences between testing modalities. Comparison of published objective measures and subjective scores shows the objective measures to be poor indicators of subjective quality. Initial results for a retrained objective measure of quality are presented with results approaching average loss and correlation values of subjective sessions. An objective measure of quality for time-scaled audio is proposed that makes use of the previously developed dataset and improves on reported results. The measure uses hand-crafted features and a fully connected network to predict subjective mean opinion scores. Basic and Advanced Perceptual Evaluation of Audio Quality features are used in addition to nine features specific to TSM artefacts. Six methods of alignment are explored, with interpolation of the reference magnitude spectrum to the length of the test magnitude spectrum giving the best performance. The proposed measure achieves an average Root Mean Squared Error (RMSE) of 0.490 and a mean Pearson Correlation Coe cient (PCC) of 0.864, equivalent to 97th and 82nd percentiles of subjective sessions respectively. The proposed measure is used to evaluate TSM algorithms, finding that Elastique gives the highest objective quality for solo instrument and voice signals, while the Identity Phase-Locking Phase Vocoder gives the highest objective quality for music signals and the best overall quality. Two single-ended objective quality measures for time-scaled audio are also proposed. These measure do not require a reference signal, nor alignment. Data driven features are created by either a convolutional neural network (CNN) or a bidirectional gated recurrent unit (BGRU) network, and are fed to a fully-connected network to predict subjective mean opinion scores. The proposed CNN and BGRU measures achieve an average RMSE of 0.608 and 0.576, and a mean PCC of 0.771 and 0.794, respectively. The proposed measures are used to evaluate TSM algorithms, and comparisons are provided for 16 TSM implementations. A literature review is included with required background knowledge. It includes the fundamentals of sound perception, sound capture, digital signal processing, time-scale modification methods used within research, and subjective and objective measures of quality. Full implementation of all proposed methods and measures can be found at github.com/zygurt/TSM, while the labelled dataset is available at http://ieee-dataport.org/1987.

A possible analysis for failure of U.S. SMAP satellite

This paper presents a study of English-Indonesian translation of the humorous utterances in Walt Disney’s Donald Duck comics. Twenty one Indonesian translated comics of the 2008 issues and their original English versions were used as the source of data. A total of 480 humorous English utterances were identified and verified by 4 native English speakers. These 480 English utterances and their translations were used as the data. Analyses of the collected data were then made to see the translation techniques used by the translator in translating the humorous utterances and to see the resulted pragmatic equivalence viewed from the equivalence of pragmatic force between the source text (ST) and target text (TT), involving implicture analysis of the utterances. The findings of the research reveal that 647 uses of translation techniques are made to translate the 480 utterances, as more than one techniques are used in some of the utterances. Seventeen out of 18 translation techniques proposed by Molina & Albir (2002) are chosen by the translator. It is also found out that the translator’s choice of translation techniques has resulted in 96.87% of the translated humorous utterances being equivalent in their pragmatic force, compared to the original English utterances. The use of such translation techniques as generalization, established equivalent, linguistic compression, amplification, literal translation, compensation, linguistic amplification, variation, particularization, borrowing, transposition, description, and calque has resulted in equivalent pragmatic force between ST and TT. Only minor portion (3.13%) of the translated text is not equivalent in its pragmatic force, and this is caused by the use of amplification, discursive creation, reduction, adaptation, and modulation techniques. The high rate of pragmatic equivalence shows the translator’s success in translating the text. Key words : implicature, pragmatic force, pragmatic equivalence, translation technique

The Sixth International Symposium on Neural Networks (ISNN 2009)

Many of today's satellite communication and radar systems necessitate phased array antennas that are capable of wideband/multi-band operation and good polarization purity over a wide scan volume. However, the antenna solutions typically used for wideband wide-scan applications trade-off matching performance against polarization purity. For this reason, in recent years, a new approach has arisen for the design of broadband arrays, aiming at reducing cross polarization. This antenna solution consists of arrays of long dipoles or slots periodically fed, and are referred to as connected arrays of slot or dipoles. Connected array antennas represent one of the most promising concepts in the field of very wideband arrays, for being able to achieve both broad band and low cross polarization. The wideband performance is due to the fact that the connections between neighboring elements allow currents to remain nearly constant with frequency. Another attractive feature of connected arrays is their capability to achieve good polarization purity, in virtue of the planarity of the radiators. Besides the advantageous physical properties, connected arrays are based on simple geometries that lead to the derivation of analytical solutions for the antenna parameters. Closed-form expressions based on a spectral Green's function representation are derived for the input impedance, the current distribution over the array and the radiation patterns. Important advantages result from this representation with respect to numerical solutions: above all, the reduction of computational costs and the gain in physical insight on the wave phenomena. A convenient circuit representation of the array unit cell is derived. The circuit describes rigorously and analytically the transition between free-space radiation and guiding transmission line. Contrarily to standard Thevenin circuit for receiving antennas, this representation can be used to evaluate the power scattered by the antenna. The results have been applied to the analysis of the scattering and absorption of a real connected-dipole prototype array backed by a frequency selective ground plane. Good agreement was achieved between measurements and results from the equivalent network. A novel measurement technique based on passive RCS measurements in the main planes was used to characterize the active matching of the radiating part of the antenna in transmission. Finiteness effects can be particularly severe in connected arrays, due to electrical connection and the high mutual coupling between the elements. As a consequence, the overall behavior of a finite wideband array can be sensibly different with respect to infinite array analysis. Thus, it is crucial to include edge effects already in the preliminary assessment of the array performance. An efficient numerical procedure is derived for the characterization of the edge effects. The method requires only one unknown per elementary cell, independently from the cell geometrical parameters. This is possible thanks to the use of an appropriate connected array Green's function in the integral equation. This procedure is of general applicability and can be used for arrays with and without backing reflectors and for arbitrary scan angle. An alternative analytical representation is also derived to provide physical insight on the nature of the edge-waves. The analytical approximation of the spatial current distribution on the finite array is derived, for the specific case of a connected array of dipoles operating in free space, and scanning only in the E-plane. The key step is to represent the total current as sum of the infinite array contribution plus edge-born waves. The final analytical expression is given in terms of Fresnel functions and allows qualitative considerations on the nature of the electric current distribution, in terms of spreading and attenuation. The analytical expressions represent a powerful tool that can be used both for modeling and design. A connected array of dipoles with 40% bandwidth, when scanning in elevation to 45o, has been designed. Practical designs require the implementation of ad hoc feed structures that avoid common-mode currents to propagate on the feed lines. This problem has been addressed and feed structures that perform common-mode rejection have been designed. Measurements form a prototype demonstrator were presented for validation and showed good performance.

OF THE DISSERTATION Adaptive OFDM Radar for Target Detection and Tracking by Satyabrata Sen Doctor of Philosophy in Electrical Engineering Washington University in St. Louis, December 2010 Research Advisor: Dr. Arye Nehorai We develop algorithms to detect and track targets by employing a wideband orthogonal frequency division multiplexing (OFDM) radar signal. The frequency diversity of the OFDM signal improves the sensing performance since the scattering centers of a target resonate variably at different frequencies. In addition, being a wideband signal, OFDM improves the range resolution and provides spectral efficiency. We first design the spectrum of the OFDM signal to improve the radar’s wideband ambiguity function. Our designed waveform enhances the range resolution and motivates us to use adaptive OFDM waveform in specific problems, such as the detection and tracking of targets. We develop methods for detecting a moving target in the presence of multipath, which exist, for example, in urban environments. We exploit the multipath reflections by utilizing different Doppler shifts. We analytically evaluate the asymptotic performance of the detector and adaptively design the OFDM waveform, by maximizing the noncentrality-parameter expression, to further improve the detection performance. ii Next, we transform the detection problem into the task of a sparse-signal estimation by making use of the sparsity of multiple paths. We propose an efficient sparse-recovery algorithm by employing a collection of multiple small Dantzig selectors, and analytically compute the reconstruction performance in terms of the `1-constrained minimal singular value. We solve a constrained multi-objective optimization algorithm to design the OFDM waveform and infer that the resultant signal-energy distribution is in proportion to the distribution of the target energy across different subcarriers. Then, we develop tracking methods for both a single and multiple targets. We propose a tracking method for a low-grazing angle target by realistically modeling different physical and statistical effects, such as the meteorological conditions in the troposphere, curved surface of the earth, and roughness of the sea-surface. To further enhance the tracking performance, we integrate a maximum mutual information based waveform design technique into the tracker. To track multiple targets, we exploit the inherent sparsity on the delay-Doppler plane to develop an computationally efficient procedure. For computational efficiency, we use more prior information to dynamically partition a small portion of the delay-Doppler plane. We utilize the block-sparsity property to propose a block version of the CoSaMP algorithm in the tracking filter.

Concrete pavement joint evaluation involves a number of assessment criteria, such as deflection near the joint, load transfer efficiency of the dowels and severity of voids under the slab. Although there are well defined thresholds for each of these parameters, often there arises a situation where each of the considered parameters lends contradictory assessment that leads to a considerable subjectivity in the evaluation process. A Self-Organizing Map (SOM), an unsupervised learning procedure in artificial neural network, is utilised for the first time to map the joint condition of concrete pavements from Falling Weight Deflectometer (FWD) deflection bowls. A novel methodology is proposed for labelling the network, whereby pavement engineering expertise can be directly used in a SOM for consistent deflection data classification in joint evaluation. The effectiveness of the trained network is demonstrated by using joint assessment parameters; namely, load transfer efficiency (LTE), void intercepts and absolute deflection. The joints were classified as good, marginal or poor. For the three parameters based SOM classification, an accuracy of 65-70% was obtained; this improves to 87.5% when the SOM was trained with 2-parameters (LTE and absolute deflection). However, when the SOM was tested with the data classified as 'good', accuracy improves to around 90%. Therefore, a SOM can be a powerful supplementary tool for a consistent and non-subjective evaluation of concrete pavement joints.

Reduction of engine development time and cost is of primary interest for combustion engine manufacturers. This reduction is complicated by the fact that it has to be realized simultaneously with the fulfilling of ever more stringent legislative demands regarding emissions of NOx and Particulate Matter (PM) and demand from the (transportation) market to reduce fuel consumption. Meeting these demands has resulted in the addition of new technologies with their own degrees of freedom. Furthermore new advanced combustion concepts, such as low-temperature high-EGR combustion are being developed. These new concepts put great demands on in-cylinder charge condition (composition, temperature, pressure) and combustion control. This has led to complex and non-transparent engine control systems which increase development time and costs. The main contribution of this work is the development of a physically-based control oriented in-cylinder CI engine combustion model which predicts the interaction between a) the fuel injection rate and rate of heat release and b) the fuel injection process and the emission of NO (main component of NOx) and soot (main component of PM) emission for both conventional and advanced, high-EGR, CI combustion. Although the model is developed to be generally applicable, the validation process has been limited to only include Heavy Duty DI diesel engines. The NO, soot and heat release rate model combine (existing) zero and one-dimensional phenomenological models. These models describe the essential combustion physics and kinetics following the latest insights on the primarily mixing-controlled diesel spray-combustion process. This physical basis distinguishes the combustion model from the majority of combustion models for control applications found in literature that have a more empirical nature. It increases the predictive capabilities of the model and makes it more generic. As a result the amount of measurement data required for model identification will be lower and will reduce development time and costs. The soot and heat release rate model are based on existing state-of-the art models from literature. They are adapted to obtain a more accurate physical basis and to allow the prediction of advanced, high-EGR, combustion. For complete model identification and validation, this thesis presents a complete chain of measurements, comprising dedicated measurement set-ups. This chain starts with the characterization of the fuel injection equipment performing mass flow rate and momentum flow rate measurements, which allows reconstructing accurately the fuel injection rate corresponding to a performed engine test. Thereafter, the fuel spray behaviour is characterized, mainly by tuning existing spray-correlations on the basis of dedicated measurement data from an optically accessible high pressure chamber (The Eindhoven High Pressure Cell). Main emission model identification and validation is performed on the basis of measured heat release rates (i.e. as derived from measured in-cylinder pressure curves) from a research-type single-cylinder Heavy Duty diesel engine. The resulting identified and validated model is directly applied to a multi-cylinder Heavy Duty diesel engine. Results show that the heat release rate and emission formation models of NO and soot show satisfactory qualitative agreement with measurements for changes in fuelling (injection timing, pressure and quantity), EGR rate and engine speed, for both conventional and high-EGR combustion with conventional timing. These results validate the use of the model as predictive tool in the control development process. For NO, quantitative accuracy is in-line with or better than comparable state-of-the-art models with a more profound empirical nature. However, the obtained accuracy is currently not sufficient to use the model as virtual NO sensor in control applications. For accurate NO prediction a high accuracy is required on the prediction of the NO formation temperature evolution. The most important phenomena that influence this evolution have been examined and implemented by physically-based models that are supported by detailed computations on laminar flamelets and homogeneous reactor models. Simulation results show that the primary NO reducing phenomena are dissociation and flame straining by turbulence. Fuel evaporative cooling and hot soot particle radiative cooling are of secondary importance. The reduction in NO formation caused by hot gas radiative cooling only has a marginal influence. Entrainment of fresh, cold, oxidizer into the hot combustion products, in which the NO formation occurs, has to be accounted for to allow accurate NO formation. Equivalent reductions cannot be obtained by aforementioned NO reducing phenomena. The prediction of NO and soot emissions from a multi-cylinder engine is significantly more accurate when the emission formation of each individual cylinders are evaluated instead of using data from only one cylinder. This requires additional sensors, which is not desirable for cost reduction. Finally, the emission formation prediction accuracy when using predicted heat release rate profiles instead of ‘measured’ curves is examined. This shows that especially a very high accuracy on the instantaneous heat release rate is required while this is of much lesser importance for accurate NO formation prediction.

Different concepts are used for the analysis and transfer of mandibular movements to virtual or conventional articulating systems. Some common procedures and analyses include the determination of the terminal hinge axis. However, despite the widespread use of different methods for hinge axis determination, very little information on the applicability and quality of these methods is currently available in the literature. The aim of this study was to provide an overview of the methods already being applied and to search for novel algorithmic methods, comparing them with respect to achievable accuracy and indication. This comparison was based on new extensive computer simulations, where the influence of measurement noise on the result of the hinge axis position could be investigated. The assumptions used for the simulations were set so that the conditions allowed for the most accurate hinge axis determination: this comprised a pure rotation during mouth opening, within an incisal pathway of 15 mm, a measurement accuracy of 50 µm, and an optimal positioning of the entire measurement setup. The results of the computer calculations show that the best accuracy can be guaranteed by the novel least squares method, introduced in this article for temporomandibular joint (TMJ) measurements. Additionally, only methods tracking two and more (iterative or parallel) independent markers or equivalent jaw position measurements provide enough information for reliable accuracy. Using actual technical equipment, the highest accuracies can be achieved in a TMJ-near measurement setup. However, even in that best-possible setup, the error of hinge axis determination cannot be expected to be less than ±1 mm. For a better characterization of actual electronic recording systems, manufacturers need to provide more insight into the evaluation processes.

One of the most important issues in buildings is irregularity in the plan or height of the structure, which causes increasing the seismic damages. In irregularity in height, sudden changes in the dynamic properties of the structure including mass, lateral stiffness and strength of the structure occur. Therefore, the stage of making decision for determining the building configuration has a fundamental importance Irregular buildings must be able to withstand the lateral forces of earthquakes and winds. One of the most common earthquake-resistant systems in steel structures is the bracing system, which has been considered by engineers due to its good performance in previous earthquakes and reduced drift of buildings. However, some architectural constraints may cause the braces to be moved to the story level, which is subjected to irregularity of cutting the lateral bearing system, or the lateral braces may be weakened or removed due to poor supervision in some stories, in which case the story may be irregular. There is very soft story in the building. In this study, 7 scenarios in three states such as regular, very soft irregularity, and irregularity of cutting the lateral bearing system is considered for 5-story frame. These frames are designed based on seismic guidelines of standard 2800, and then, the performance of them has been evaluated by SAP‌2000 software using analyses methods such as equivalent static, spectral dynamics and time history dynamics under near-fault earthquakes. The aim of this study is to investigate the accuracy of these methods. The results showed that time history dynamic analysis is more accurate than other methods. For example, the error rate of the maximum displacement response of frame with irregularity of cutting the lateral bearing system in equivalent static analysis compared to spectral and time history dynamic analyses are 15% and 77%, respectively.

We derive an adaptive solver for random elliptic boundary value problems, using techniques from adaptive wavelet methods. Substituting wavelets by polynomials of the random parameters leads to a modular solver for the parameter dependence, which combines with any discretization on the spatial domain. We show optimality properties of this solver, and present numerical computations. Introduction Stochastic Galerkin methods have emerged in the past decade as an efficient solution procedure for boundary value problems depending on random data, see [DBO01, XK02, BTZ04, WK05, MK05, FST05, WK06, TS07, BS09, BAS10]. These methods approximate the random solution by a Galerkin projection onto a finite dimensional space of random fields. This requires the solution of a single coupled system of deterministic equations for the coefficients of the Galerkin projection with respect to a predefined set of basis functions on the parameter domain. A major remaining obstacle is the construction of suitable spaces in which to compute approximate solutions. These should be adapted to the stochastic structure of the equation. Simple tensor product constructions are infeasible due to the high dimensionality of the parameter domain in case of input random fields with low regularity. Parallel to but independently from the development of stochastic Galerkin methods, a new class of adaptive methods has emerged, which are set not in the continuous framework of a boundary value problem, but rather on the level of coefficients with respect to a hierarchic Riesz basis, such as a wavelet basis. Due to the norm equivalences constitutive of Riesz bases, errors and residuals in appropriate sequence spaces are equivalent to those in physically meaningful function spaces. This permits adaptive wavelet methods to be applied directly to a large class of equations, provided that a suitable Riesz basis is available. For symmetric elliptic problems, the error of the Galerkin projection onto the span of a set of coefficients can be estimated using a sufficiently accurate approximation of the ∗Research supported in part by the Swiss National Science Foundation grant No. 200021-120290/1.

Long term supporting schemes for photovoltaic (PV) system installation have led to accommodating large numbers of PV systems within load pockets in distribution grids. High penetrations of PV systems can cause new technical challenges, such as voltage rise due to reverse power flow during light load and high PV generation conditions. Therefore, new strategies are required to address the associated challenges. Moreover, due to these changes in distribution grids, a different response behavior of the distribution grid on the transmission side can be expected. Hence, a new equivalent model of distribution grids with high penetration of PV systems is needed to be addressed for future power system studies. The thesis contributions lie in three parts. The first part of the thesis copes with the PV modelling. A non-proprietary PV model of a three-phase, single stage PV system is developed in PSCAD/EMTDC and PowerFactory. Three different reactive power regulation strategies are incorporated into the models and their behavior are investigated in both simulation platforms using a distribution system with PV systems. In the second part of the thesis, the voltage rise problem is remedied by use of reactive power. On the other hand, considering large numbers of PV systems in grids, unnecessary reactive power consumption by PV systems first increases total line losses, and second it may also jeopardize the stability of the network in the case of contingencies in conventional power plants, which supply reactive power. Thus, this thesis investigates and develops the novel schemes to reduce reactive power flows while still keeping voltage within designated limits via three different approaches: 1. decentralized voltage control to the pre-defined set-points 2. developing a coordinated active power dependent (APD) voltage regulation Q(P) using local signals 3. developing a multi-objective coordinated droop-based voltage (DBV) regulation Q(V) using local signals In the third part of the thesis, furthermore, a gray-box load modeling is used to develop a new static equivalent model of a complex distribution grid with large numbers of PV systems embedded with voltage support schemes. In the proposed model, variations of voltage at the connection point simulate variations of the model’s active and reactive power. This model can simply be integrated into load-flow programs and replace the complex distribution grid, while still keeping the overall accuracy high. The thesis results, in conclusion, demonstrate: i) using rms-based simulations in PowerFactory can provide us with quite similar results using the time domain instantaneous values in PSCAD platform; ii) decentralized voltage control to specific setpoints through the PV systems in the distribution grid is fundamentally impossible due to the high level voltage control interaction and directionality among the PV systems; iii) the proposed APD method can regulate the voltage under the steady-state voltage limit and consume less total reactive power in contrast to the standard characteristic Cosf (P) proposed by German Grid Codes; iv) the proposed optimized DBV method can directly address voltage and successfully regulate it to the upper steady-state voltage limit by causing minimum reactive power consumption as well as line losses; v) it is beneficial to address PV systems as a separate entity in the equivalencing of distribution grids with high density of PV systems.

The main goal of the study is to analyze all relevant properties of the electro hydraulic systems and based on that to make a proper choice of the control strategy that may be used for the control of the servomechanism system. A combination of electronic and hydraulic systems is widely used since it combines the advantages of both. Hydraulic systems are widely spread because of their properties as accuracy, flexibility, high horsepower-to-weight ratio, fast starting, stopping and reversal with smoothness and precision, and simplicity of operations. On the other hand, the modern control of hydraulic systems is based on control of the circuit fed to the inductive solenoid that controls the position of the hydraulic valve. Since this circuit may be easily handled by PWM (Pulse Width Modulation) signal with a proper frequency, the combination of electrical and hydraulic systems became very fruitful and usable in specific areas as airplane and military industry. The study shows and discusses the experimental results obtained by the control strategy (classical feedback (PID) & neural network) using MATLAB and SIMULINK [1]. Finally, the special attention was paid to the possibility of neuro-controller design and its application to control of electro-hydraulic systems and to make comparative with classical control.

Radar emitter identification has been studied for decades using library-based techniques that rely on pre-existing knowledge of parameters such as radio frequency (RF), pulse amplitude, pulse width, intentional pulse modulation type, or pulse repetition intervals. However, current radar emitter identification techniques will not be sufficient against cognitive radars due to their parameter agility and adaptability. In this study, five radar emitter identification fingerprints based on radar signal transients were analyzed and compared. These fingerprints include: (1) fractal dimension estimation of signal transients, (2) natural measures of signal transients, (3) polynomial regression of a signal transient energy trajectory acquired by its 4th order cumulants, (4) RF fingerprints based on the energy trajectory characteristics of signal transients, and (5) intrinsic shape of the rising edge of a pulse. The analysis and comparison were performed using K-Nearest Neighbours, Quadratic Discriminant Analysis, and relative entropy over a dataset from five different radar emitters. The advantages and drawbacks of each technique are highlighted. Our results show that (2), (4) and (5) achieve very competitive emitter identification performance using the selected radar datasets and classification algorithms. This study also demonstrates that the optimal emitter identification performance is dependent on the combination of RF fingerprints and classification algorithms.