Radar target tracking problem has been a popular topic for several decades. Recent works have shown that the performance of tracking algorithms increases as more prior information is used by the system / such as maximum velocity and maximum acceleration of the target, altitude of the target, or the elevation structure of the terrain. In this thesis we will focus on increasing the performance of tracking algorithms making use of benefit from the elevation model of the environment where the target tracker is searching. For a constant target altitude and a certain radar location, we generate a &ldquo / visibility map&rdquo / using the elevation model of the terrain and use this information to estimate the location and the time that the target will reappear. The second aim of this work is to use the visibility map information for improving the performance of track initiation. For that purpose, a special map has been formed, that we call as the &ldquo / track initiation probability map&rdquo / , which shows the target first time appearance density. This information has been used at the initialization part of the track initiation algorithm in order to increase the performance.

In this thesis a number of improvements have been established for specific methods which utilize sequential Monte Carlo (SMC), aka. Particle filtering (PF) techniques. The first problem is the Bayesian multi-target tracking (MTT) problem for which we propose the use of non-parametric Bayesian models that are based on time varying extension of Dirichlet process (DP) models. The second problem studied in this thesis is an important application area for the proposed DP based MTT method / the tracking of vocal tract resonance frequencies of the speech signals. Lastly, we investigate SMC based parameter estimation problem of nonlinear non-Gaussian state space models in which we provide a performance improvement for the path density based methods by utilizing regularization techniques.

Sonar is the traditional method of underwater target detection and tracking. However, using traditional sonar arrays may be difficult and impractical in some mission-critical scenarios as they require a ship or a submersible to be mounted on or towed by. Alternatively, Underwater Acoustic Sensor Networks (UW-ASN) offer a promising solution approach. In this thesis, a target tracking algorithm for UW-ASN, Three-Dimensional Underwater Target Tracking (3DUT) is presented. The objective of 3DUT is to collaboratively accomplish accurate tracking of underwater targets with minimum energy expenditure. Based on the time-of-arrival (ToA) of the echoes from the target after transmitting acoustic pulses from the sensors, the ranges of the nodes to the target are determined, and trilateration is used to obtain the location of the target. The location and the calculated velocity of the target are then exploited to achieve tracking. In order to realize energy-effective target tracking, 3DUT incorporates a new target movement-based duty cycle mechanism. To avoid rapid depletion of energy resources of boundary nodes due to continuous surveillance, 3DUT employs an adaptive procedure to find, designate, and activate new boundary nodes. Performance evaluation shows that 3DUT is a promising alternative to the traditional sonar based target tracking approaches especially for on-demand surveillance applications.

The aim of this study is to investigate the place of the students&amp / #8223 / native culture in the English language classrooms in the context of the English 101 course at Middle East Technical University. In accordance with this aim, the study is concerned with revealing the opinions and beliefs of language teachers regarding the importance of integrating the students&amp / #8223 / native cultures into their classes and their attitudes about practicing culturally responsive teaching in multi-cultural classrooms. During the process of data collection, various methods were utilized: Five teachers working in the Department of Modern Languages were interviewed to learn their ideas about the topic from different aspects of language instruction, and two teachers were observed while teaching to better understand the classroom application of their ideas and the principles of culturally responsive teaching. Further post-observation interviews and stimulated recalls were also carried out to make an in-depth analysis. The results of the study show that although the teachers believe in the importance of making use of the students&amp / #8223 / native cultures in their classrooms through different means, they usually neglect to do so. The study also shows that what the teachers associate with the term &ldquo / culture&rdquo / in the context of language teaching is the target culture rather than the native cultures. It is also found that while the individual cultures of the foreign students are made use of to a greater degree (but still in a very limited fashion), the native cultures of the Turkish students are ignored during the instruction.

Airburst projectiles increase the effectiveness of air defense, by forming clouds of small pellets. In this work, in order to evaluate the effectiveness of airburst projectiles, Single Shot Kill Probability (SSKP) is computed at different burst distances by using three lethality functions defined from different measures of effectiveness. These different measures are target coverage, number of sub-projectile hits on the target and kinetic energy of sub-projectiles after burst. Computations are carried out for two different sub-projectile distribution patterns, namely circular and ring patterns. In this work, for the determination of miss distance, a Monte Carlo simulation is implemented, which uses Modified Point Mass Model (MPMM) trajectory equations. According to the results obtained two different distribution patterns are compared in terms of effectiveness and optimum burst distance of each distribution pattern is determined at different ranges.

The aim of this thesis is to design a controller for an unmanned helicopter to perform target engagement. This mission is briefly defined as / the helicopter flies to a firing point under the commands of a trajectory controller, and then it is aligned to the target with attitude control. After weapon firing, the helicopter initiates a return maneuver under again the commands of the trajectory controller. This mission where the continuous systems and discrete guidance decisions are to be executed in coherence can be studied as a hybrid control problem. One hybrid control approach which is used in this study is the representation based on two motion primitives: trim trajectories and maneuvers. To obtain the desired trim trajectories and the maneuvers, a dynamic inversion based controller is developed. The controller has two loops: the inner loop which controls the helicopter attitudes and the outer loop which controls the helicopter trajectory. A guidance algorithm is developed which enables the controller to switch from the inner loop to the outer loop or vice versa. Simulations are generated to test the controller performance.

In this study Track Before Detect (TBD) approach will be analysed for tracking of dim moving targets. First, a radar setup is presented in order to introduce the radar range equation and signal models. Then, preliminary information is given about particle filters. As the main algorithm of this thesis, a multi-model particle filter method is developed in order to solve the non-linear non-Gaussian Bayesian estimation problem. Probability of target existence and RMS estimation accuracy are defined as the performance parameters of the algorithm for very low SNR targets. Simulation results are provided and performance analysis is presented as a conclusion.

Nonlinear response history analysis is considered as the most accurate analytical tool for estimating seismic response. However, there are several shortcomings in the application of nonlinear response history analysis, resulting from its complexity. Accordingly, simpler approximate nonlinear analysis procedures are preferred in practice. These procedures are called nonlinear static analysis or pushover analysis in general. The recently developed Generalized Pushover Analysis (GPA) is one of them. In this thesis study, GPA is presented and evaluated comparatively with the nonlinear time history analysis and modal pushover analysis. A generalized pushover analysis procedure was developed for estimating the inelastic seismic response of structures under earthquake ground excitations (Sucuoglu and G&uuml / nay, 2011). In this procedure, different load vectors are applied separately to the structure in the incremental form until the predefined seismic demand is obtained for each force vector. These force vectors are named as generalized force vectors. A generalized force vector is a combination of modal forces, and simulates the instantaneous force distribution on the system when a given response parameter reaches its maximum value during the dynamic response. In this method, the maximum interstory drift parameters are selected as target demand parameters and used for the derivation of generalized force vectors. The maximum value of any other response parameter is then obtained from the analysis results of each generalized force vector. In this way, this procedure does do not suffer from the statistical combination of inelastic modal responses. It is further shown in this study that the results obtained by using the mean spectrum of a set of ground motions are almost identical to the mean of the results obtained from separate generalized pushover analyses under each ground motion in the set. These results are also very close to the mean results of nonlinear response history analyses. A practical implementation of the proposed generalized pushover analysis is also developed in this thesis study where the number of pushovers is reduced in view of the number of significant modes contributing to seismic response. It has been demonstrated that the reduced generalized pushover analysis is equally successful in estimating maximum member deformations and member forces as the full GPA under a ground excitation, and sufficiently accurate with reference to nonlinear response history analysis.

The purpose of the present study was to investigate the cultural load of the reading texts of the Spot On 8 ELT textbook published in Turkey, and to find out the teachers&rsquo / and students&rsquo / perceptions concerning the presence of native, target and other world cultures (C1, C2 and C3 respectively) in ELT textbooks. In order to fulfill these aims, a checklist, a teacher questionnaire, a student questionnaire, a teacher interview were developed by the researcher. Moreover, the impressionistic overview and the item frequency procedure were applied for the analysis of cultural content of the textbook. Quantitative data were analyzed by calculating the frequencies, percentages, and the Chronbach alpha. Qualitative data were analyzed by applying the coding system for the categorization of collected responses and content analysis. The results showed that the cultural load of the textbook was insufficient and that the percentage of cultural elements in the reading passages is significantly low. The teachers&rsquo / satisfaction with the textbook appeared to be relatively low and students showed neither high level of satisfaction with their textbook nor dissatisfaction with it. Overall, there is a serious mismatch between teachers&rsquo / and students&rsquo / perceptions of culture and the real cultural load of the textbook. The target culture prevails in the reading texts although teachers considered native and other world cultures to be important as well, and students showed equally low interest in target and other world cultures giving the preference dominantly to their native culture.

Within the air defense domain, the Weapon-Target Allocation problem is a fundamental problem. This problem deals with the allocation of a set ofiring units or weapons to a set of hostile targets so that the total expected effect on targets is maximized. The Weapon-Target Allocation problem has been proven to be NP-Complete by Lloyd and Witsenhausen [14]. In this thesis, the use of various algorithms including search algorithms, maximum marginal return algorithms, evolutionary algorithms and bipartite graph matching algorithms are demonstrated to solve the problem. Algorithms from the literature are adjusted to the problem and implemented. In addition, existing algorithms are improved by taking care of the maximum allowed time criterion. A testbed is developed to be able to compare the algorithms. The developed testbed allows users to implement new algorithms and compare the algorithms that are selected by the users easily. Using the testbed, implemented algorithms are compared based on optimality and performance criteria. The results are examined and by combining the algorithms that give better results, a new algorithm is proposed to solve the problem more effciently. The proposed algorithm is also compared to the other algorithms and computational results of the algorithms are presented.