Design of multiband CMOS mixers for low-voltage low-power applications

In this thesis, the design of low-power low-voltage CMOS mixers for wireless communication applications has been explored.Master of Engineerin

Design of high-speed low-power clock and data recovery circuit

In this thesis, the design of fully integrated high-speed low-power clock and data recovery (CDR) circuits in complementary metal-oxide-semiconductor (CMOS) devices for synchronous optical network (SONET) applications has been explored.DOCTOR OF PHILOSOPHY (EEE

Employing remote sensing technique to monitor the influence of newly established universities in creating an urban development process on the respective cities

Universities have a wide range of effects on the development of the cities, economic growth and socio-cultural structures of the communities. Accordingly, the Turkish government has encouraged the establishment of the higher education institutions to support the regional development especially in the underdeveloped areas. In this study, 13 universities established after 2006 in the eastern and south-eastern regions of the country were analysed for the determination of the effects of the university establishments in the land use patterns. To fulfil this aim NDVI differencing technique covering a period of 10–13 years was performed within the 1 km, 3 km and 5 km buffer rings around the campuses as well as the city centres. The city centres of three additional universities from the same region with older establishment periods varying between 1950 and 1980 were also analysed to compare the results. The results showed that the average of the negative changes in the city centre boundaries was 4.49%, and 6 of the 13 universities conduced to urban development, whereas the remaining 7 ones did not create a significant urban development

Determination of the nighttime light imagery for urban city population using DMSP-OLS methods in Istanbul

© 2020, Springer Nature Switzerland AG.Demography researchers and scientists have been effectively utilizing advanced technologies and methods such as geographical information systems, spatial statistics, georeferenced data, and satellite images for the last 25 years. Areal interpolation methods have also been adopted for the development of population density maps which are essential for a variety of social and environmental studies. Still, a good number of social scientists are skeptical about such technologies due to the complexity of methods and analyses. In this regard, a practical intelligent dasymetric mapping (IDM) tool that facilitates the implementation of the statistical analyses was used in this study to develop the population distribution map for the Istanbul metropolitan area via night light data provided by the Defense Meteorological Satellite Program’s Operational Linescan System (DMSP-OLS) and the census records of the study area. A population density map was also produced using the choropleth mapping method to enable to make a comparison of the traditional and intelligent population density mapping implementations. According to the dasymetric population density map, 38.5% of the study area fell into sparse density category while low, moderate, high, and very high population density class percentages were found to be 9.4%, 5.5%, 2.9%, and 0.1% respectively. On the other hand, the percentages of the same population density classes ranking from sparse to very high in the choropleth map were determined to be 90.7%, 7.3%, 1.7%, 0.3%, and 0%. In the change analysis made as a result of the classification, the changes between the city area and the population were revealed. During this period, the city area and population grew. Spatial change has also been interpreted by comparing it with population changes. There appears to be a remarkable increase in both surface area and population. It is observed that the increase is especially in the south and northwest of the city. With the population increase, the number of new residential areas has increased. It is thought that behind this growth, there are different reasons besides the effect of the increase in residential areas. When the environmental awareness of people has increased more than in the past centuries, new solutions should be produced in order to be more controlled, smart, and sustainable while planning the cities of the future. Considering that the development of technology and remote sensing techniques is progressing in parallel with this technology, this study in which GIS technologies integrated with satellite images are used, it is thought that it will contribute positively to the studies in this area in terms of regular development of urban areas, increasing the opportunity to make fast and correct decisions, and creating infrastructure for studies such as monitoring and prevention of illegal housing

Assessing the effects of wind farms on soil organic carbon.

Wind energy is considered one of the cleanest and most sustainable resources among renewable energy sources. However, several negative environmental impacts can be observed, unless suitable sites are selected for the establishment of wind farms. The aim of this study is to determine the change in the soil organic carbon (SOC) stock resulting from land cover changes that were caused by wind farm establishments in the Karaburun peninsula. Within the scope of the study, remote sensing and geographic information system technologies were utilized. Maximum likelihood algorithm, one of the supervised classification techniques, was used to classify the land cover, and Normalized Difference Vegetation Index (NDVI) analyses were performed to determine land cover changes. The findings were correlated with the “Turkey Soil Organic Carbon Project” data. As a result, depending on the establishment of wind farms in the Karaburun Peninsula, a total decrease of 18,330.57 tons of SOC in the study area between 2000 and 2019 was determined. It should be taken into consideration that besides many other negative effects (effects on human health, effects on the ecosystem, effects on animals, etc.), land cover changes caused by wind farms may indirectly cause important problems such as climate change. Recently, this situation shows that there is an important dilemma in terms of current implementations. Wind farms are the most invested renewable energy sources and alternative energy supply to fossil fuels in terms of preventing climate change. However, the results of this study have reviewed that lack of proper approaches and methods to establish wind farms may result in various problems such as physical, chemical, and biological degradations and an increase in the amount of atmospheric carbon. Consequently, the investments in renewable energy sources should be comprehensively reevaluated in terms of current technologies, quality in the scope of environmental impact assessment and strategic environmental assessment processes, legal regulations and national policies, long-term environmental costs, etc

An energy-aware CMOS receiver front end for low-power 2.4-GHz applications

A receiver front end designed in 0.18- um CMOS consisting of a low-noise amplifier and IQ mixers is presented. The front end’s power consumption is controllable from 5.0 down to 1.4 mA. It is proposed to push the receiver requirements to the front end in order to efficiently control the overall power consumption based on the real-time required noise performance. We show that, under good channel conditions, this front end can save up to 70% of its nominal power consumption.Published versio