Regional flood frequency techniques are commonly used to estimate flood quantiles when flood data are unavailable or the record length at an individual gauging station is insufficient for reliable analyses. These methods compensate for limited or unavailable data by pooling data from nearby gauged sites. This requires the delineation of hydrologically homogeneous regions in which the flood regime is sufficiently similar to allow the spatial transfer of information. Therefore, several Regional Flood Frequency Analysis (RFFA) methods are applied to the Ceyhan Basin. Dalyrmple (1960) Method is applied as a common RFFA method used in Turkey. Multivariate statistical techniques which are Stepwise and Nonlinear Regression Analysis are also applied to flood statistics and basin characteristics for gauging stations. Rainfall, Perimeter, Length of Main River, Circularity, Relative Relief, Basin Relief, Hmax, Hmin, Hmean and H&Delta / are the simple additional basin characteristics. Moreover, before the analysis started, stations are clustered according to their basin characteristics by using the combination of Ward&rsquo / s and k-means clustering techniques. At the end of the study, the results are compared considering the Root Mean Squared Errors, Nash-Sutcliffe Efficiency Index and % difference of results. Using additional basin characteristics and making an analysis with multivariate statistical techniques have positive effect for getting accurate results compared to Dalyrmple (1960) Method in Ceyhan Basin. Clustered region data give more accurate results than non-clustered region data. Comparison between clustered region and non-clustered region Q100/Q2.33 reduced variate values for whole region is 3.53, for cluster-2 it is 3.43 and for cluster-3 it is 3.65. This show that clustering has positive effect in the results. Nonlinear Regression Analysis with three clusters give less errors which are 29.54 RMSE and 0.735 Nash-Sutcliffe Index, when compared to other methods in Ceyhan Basin.

During shearing of stiff clays, plate-shaped clay particles are parallel-oriented in the direction of shear reaching the minimum resistance of &ldquo / residual shear strength&rdquo / . The residual shear strength envelopes of stiff clays are curved, but for practical purposes represented by linear envelopes. This study investigates the nonlinearity of the residual shear strength envelope using experimental evidence (i) from laboratory reversal direct shear tests on two stiff clays (Ankara clay and kaolinite) at 25 to 900 kPa effective normal stresses and (ii) from laboratory data collected from literature. To evaluate the importance of nonlinearity of the envelope for geotechnical engineering practice, by limit equilibrium method, (a) case histories of reactivated landslides are analyzed and (b) a parametric study is carried out. Conclusions of this study are: (1) The residual shear strength envelopes of both Ankara clay and kaolinite are nonlinear, and can be represented by a power function (cohesion is zero). (2) At least 3 reversals or cumulative 20 mm shear displacement of direct shear box is recommended to reach residual condition. (3) Empirical relations between plasticity index and residual friction angle can accurately estimate the residual strength of stiff clays. (4) Nonlinearity is especially important for landslides where average effective normal stress on the shear plane is less than 50 kPa, both for translational and rotational failures. For such slopes using a linear strength envelope overestimates the factor of safety (more significantly for the case of high pore pressures). (5) As the plasticity index increases, the power &ldquo / b&rdquo / of the nonlinear shear strength envelope decreases, indicating more significant nonlinearity. For less plastic materials, using linear and nonlinear shear strength envelopes does not affect the factor of safety.

In this thesis, sensitivity and error analysis of a differential rectification method were performed by using digital images taken by a frame camera onboard BILSAT and pushbroom scanner on ASTER. Three methods were implemented for Sensitivity and Uncertainty analysis: Monte Carlo, covariance analysis and FAST (Fourier Amplitude Sensitivity Test). A parameter estimation procedure was carried out on the basis of so called Mixed Model extended by some suitable additional regularization parameters to stabilize the solution for improper geometrical conditions of the imaging system. The effectiveness and accuracy of the differential rectification method were compared with other rectification methods and the results were analyzed. Furthermore the differential method is adapted to the pushbroom scanners and software which provides rectified images from raw satellite images was developed.

In this thesis, an intelligent controller for gun and/or sight stabilization of turret subsystems is developed using artificial neural networks. A classical proportional, integral and derivative (PID) controller equipped with a non-linear unbalance compensation algorithm is used as the low-level controller. The gains of this PID controller are tuned using a multilayered back-propagation neural network. These gains are modeled as a function of the error between the command and feedback signals and this model is generated by the function fitting property of neural networks as an estimate. The network is called as the &ldquo / Neural PID Tuner&rdquo / and it takes the current and previous errors as inputs and outputs the PID gains of the controller. Columb friction is the most important non-linearity in turret subsystems that heavily lower the efficiency of the controller. Another multilayered back-propagation neural network is used in order to increase the performance of the PID controller by identifying and compensating this Columb friction. This network utilizes the error between the output of the PID controller driving the physical system with Columb friction and the output of the identical PID controller driving a virtual equivalent linear system without Columb friction. The linear dynamics of the physical system is identified using a single layer linear neural network with pure linear activation function and the equivalent virtual linear system is emulated using this identification. The proposed methods are applied to both computer simulations and hardware experimental setup. In addition, sensitivity and performance analysis are performed both by using the mathematical model and hardware experimental setup.

The objective of this study is to determine hydrate formation conditions of methane- hydrogen sulfide mixtures. During the study, an experimental work is carried out by using a system that contains a high-pressure hydrate formation cell and pressure-temperature data is recorded in each experiment. Different H2S concentrations and both brine and distilled water are used in the experiments and the Black Sea conditions, which are suitable for methane-hydrogen sulfide hydrate formation are examined. Considering the pressure-temperature data obtained, hydrate equilibrium conditions are determined as well as the number of moles of free gas in the hydrate formation cell. The change in the number of moles of free gas in the hydrate formation cell with respect to time is considered as a way of determining rate of hydrate formation. Effects of H2S concentration and salinity on hydrate formation conditions of methane-hydrogen sulfide mixtures are also studied. It is observed that an increase in the salinity shifts the methane-hydrogen sulfide hydrate equilibrium condition to lower equilibrium temperatures at a given pressure. On the other hand, with an increase in H2S concentration the methane hydrogen sulfide hydrate formation conditions reach higher equilibrium temperature values at a given pressure. After the study, it can be also concluded that the Black Sea has suitable conditions for hydrate formation of methane hydrogen sulfide mixtures, considering the results of the experiments.

Group of piles are widely used deep foundation systems to resist lateral and vertical loads. Seismic and static performance of pile groups mostly depend on soil type, pile spacing and pier rigidity. Not many pile lateral load tests have been performed due to high costs. Advanced and complex analytical methods were developed over the years to assess nonlinear lateral pile response. This research is conducted aiming at developing a practical analysis method to verify the lateral performance of pile groups and its effect on overall response of bridge utilizing the available pile lateral load test data. Empirical constants derived from evaluation of lateral load tests are used in a simple formulation to define the nonlinear behavior of the pile-soil system. An analysis guideline is established to model the nonlinear soil-bridge interaction by the help of a general purpose structural analysis program comprising recommendations for various cases. Results of the proposed method is compared to the results of industry accepted advanced methods using response spectrum and nonlinear time history analyses to assess the suitability of this new application. According to the analysis results, proposed simple method can be used as an effective analysis tool for the determination of response of the superstructure.

Crime is a behavior disorder that is an integrated result of social, economical and environmental factors. In the world today crime analysis is gaining significance and one of the most popular subject is crime prediction. Stakeholders of crime intend to forecast the place, time, number of crimes and crime types to get precautions. With respect to these intentions, in this thesis a spatio-temporal crime prediction model is generated by using time series forecasting with simple spatial disaggregation approach in Geographical Information Systems (GIS). The model is generated by utilizing crime data for the year 2003 in Bah&ccedil / elievler and Merkez &Ccedil / ankaya police precincts. Methodology starts with obtaining clusters with different clustering algorithms. Then clustering methods are compared in terms of land-use and representation to select the most appropriate clustering algorithms. Later crime data is divided into daily apoch, to observe spatio-temporal distribution of crime. In order to predict crime in time dimension a time series model (ARIMA) is fitted for each week day, Then the forecasted crime occurrences in time are disagregated according to spatial crime cluster patterns. Hence the model proposed in this thesis can give crime prediction in both space and time to help police departments in tactical and planning operations.

The aim of this thesis is to determine the state of occupational health and safety of the construction industry among other industries in Turkey. For this purpose, data such as the number of occupational diseases, the number of occupational injuries, the number of cases of permanent incapacity to work and the number of fatal occupational injuries in each industry are derived from official sources. The comparison of the construction industry with other industries in terms of occupational health and safety is made with the comparative measures calculated with these data. In addition, it is intended to determine some characteristics of the occupational injuries and victims in the construction industry. Therefore, the distribution of more than 22,700 data concerning occupational injuries according to some selected variables is taken into account.

In this study, the load bearing behavior of piled raft foundations is investigated performing laboratory and field tests. Piled raft foundation of a multi storey building was also instrumented and monitored in order to study the load sharing mechanism of piled raft foundations. A small reinforced concrete piled raft of 2.3 m square supported by four mini piles at the corners was loaded and contribution of the raft support up to 41 % of the total load was observed. The soil was stiff fissured Ankara clay with no ground water. A building founded on a piled raft foundation was instrumented and monitored using earth pressure cells beneath the raft during its construction period. The foundation soil was a deep graywacke highly weathered at the upper 10 m with no ground water. The proportion of load that was carried by the raft was 21 to 24 % of the total load near the edge and 44 to 56 % under the core. In the laboratory tests, model aluminum piles with outerinner diameters of 2218 mm and a length of 200 mm were used. The raft was made of steel plate with plan dimensions of 176 mm x 176 mm and a thickness of 10 mm. The model piles were instrumented with strain gages to monitor pile loads. Model piled raft configurations with different number of piles were tested. The behavior of a single pile and the plain raft were also investigated. The soil in the model tests was half and half sand &ndash / kaolinite mixture. It has been observed that when a piled raft is loaded gradually, piles take more load initially and after they reach their full capacity additional loads are carried by raft. The proportion of load that was carried by the raft decreases with the increasing number of piles and the load per pile is decreased. Center, edge and corner piles are not loaded equally under rafts. It has been found that rafts share foundation loads at such levels that should not be ignored.

Since 1976, the General Directorate of Disaster Affairs of Turkey has deployed several strong-motion accelerographs at selected sites. Within the framework of the project entitled Compilation of National Strong Ground Motion Database in Accordance with International Standards, initiated in 2006, site conditions at a total of 153 strong-motion sites were investigated within the uppermost 30 m depth through boreholes including Standard Penetration Testing and surface seismics by means of Multi-channel Analysis of Surface Waves (MASW). In this study, firstly, the assessment of the site characterization was held by making use NEHRP Provisions, EC-8 and Turkish Seismic Design Code. The corrected penetration resistances are calculated and observed how it affects the classification. In addition, the consistency of site classes obtained from either penetration resistance or shear wave velocity criteria is examined. Also the consistency of the boundaries of the site classes in terms of shear wave velocity and penetration resistance data pairs are investigated. Secondly, the liquefaction potential of these sites is examined. Thirdly and finally, the shear wave velocity profiles obtained from MASW technique are contrasted to other seismic tests.