Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7755
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Master Thesis B and Se Transport Modeling in Saturated/Unsaturated Zones(Izmir Institute of Technology, 2002) Yüreklitürk, O. Emin; Tayfur, GökmenThere has been renewed interest in the application of models to the transport of non-point source pollutants. However, very little work has been done to evaluate the performance of a functional transient-state model for the transport of a reactive solute over an extensive study period. This research consists of mathematical modeling to simulate water flow, boron and selenium transport through soil in tile-drained croplands.For Boron part a mathematical model was developed to simulate non-conservative boron transport. The dynamic two-dimensional finite element model simulates water flow and boron transport in saturated-unsaturated soil system, including boron sorption and boron uptake by root-water extraction. Two different models have been employed for the sorption of boron. Similarly, for selenium part a finite element model is developed to simulate species of selenium transport in two dimensions in saturated/unsaturated zones. The model considers water, selenate, selenite and selenomethionine uptake by plants. It also considers oxidation/reduction, volatilization, and chemical and biological transformations of selenate, selenite, and selenomethionine. Comparison of boron transport model results with observed data is satisfactory. The model employed with Langmuir isotherm was found to give slightly better simulation results when compared with the model employed with Freundlich. The sensitivity analysis results indicate that the irrigation scheduling and the irrigation water quality are very important parameters for boron accumulation in the soil. Also the adsorption isotherm parameters, which reflect us the soil properties, are found to be important for the boron movement in the soil. Comparison of selenium transport model with observed data is not quite satisfactory in accuracy when compared with the model for boron transport. This may be the result of the complexity of the mechanisms affecting the selenium transport in soil. There are too many parameters, and due to the errors depending on the parameters, the total error for the estimation of the total selenium increases.Master Thesis Managing the Risk of Contractor Failure(Izmir Institute of Technology, 2009) Yağmuroğlu, Zeynep; Günaydın, Hüsnü MuratThe topic of contractor failure has become a major research domain since the beginning of the 1980s. Construction is a risky business with many features like long period of time, complicated process, financial intensity, environment and dynamic organizational structure. The aim of this thesis is to find out the factors effecting contractor failure. In the first phase contractor failure ratio for public procurement is found by investigating the data of the Turkish Ministry of Public Works and Settlement between the years 1999 and 2006. It is found that 10.5% of the public projects end in construction default. The second phase of the study involves a questionnaire survey to find out why construction companies fail in Turkey. The first part of the questionnaire includes the determinants used by Dun and Bradstreet as the causes of failure classified as organizational, environmental, and performance factors. The second part of the questionnaire includes questions about the organizational structure of the company. It is found that the most effective causes of contractor failure are receivable difficulties, insufficient capital, lack of managerial experience, lack of business knowledge, and family problems. It is observed that ego problems, removing performance barriers, monitoring of performance, adaptation to modern work models, and clarified directions are found as major problem areas for the organizational structure of the company. Key Words: Risk Management, Construction Industry, Contractor, Failures.Master Thesis Development of Reinforced Pmma Sheets for Office Furnitures and a New Junction Detail Proposal(Izmir Institute of Technology, 2006) Özçiftçi, Sibel; Ergül, EmreNowadays life styles are changing and more modern than before, for that reason peoples furniture desires are different. In this modern world; furniture using gain a meaning and play important role than before, it defines peopele.s social status and their posion in this life. Design criteria are changing and improving everyday because of this designers use different equipments for their desingns. Glass production which is diffucult to take a shape hence plastic meterials were common after World War II. Modern views and their strength transperent materials satisfied designers desires. After gained environment conclousness same plastics which are non recyling products were gave up to use. Light and high strength plastic which is a recyling material PMMA is very common to use PMMA as known as a brand which name is plexiglass in Turkey. Also this plastic materials have very effective features than others.. İn this study, transparent sheets, glass and PMMA which are used furniture production were studied. As a designer approach different examples and combine details are given.Combine details which are used furniture production were researched and PMMA panel's strength,variety and flexibility were suggested as an beneficial metarial. After the performance, for the office furnitures, there had been a suggestion on a material that brings positive reaction for its endurance, variation and elasticity to the PMMA plate which is more frequently preferred compared with glass. In the suggested material, putting galvanized matting string between the two PMMA plates resulted in stronger and more elasticity characteristics,compared to the standart PMMA plate. After the compose of the material, it had been put through durability test.As a result the material's bending durability had been calculated, too.Master Thesis Evalution of Stone Weathering of Aigai Bouleuterion After Its Excavation(Izmir Institute of Technology, 2009) Kaplan, Çağlayan Deniz; İpekoğlu, BaşakArchaeological sites have to be investigated and conserved as a whole to have a better knowledge of our past. In this study, Aigai Bouleuterion in Manisa was investigated to evaluate the stone weathering and conservation problems of an excavated archaeological monument. It is also aimed to analyze the weathering process of stone material while buried and the contribution of this process to the deterioration after the excavation. For this purpose, the building was documented by photographs and drawings and several laboratory studies were carried out on both the soil and stone samples collected from the excavated parts of the building. Samples were investigated with by using XRD, SEM-EDX, TGA and FT-IR and chemical analyses. Andesite, used as a building material of the bouleuterion and the soils are both composed of the minerals of microline, orthoclase, sanidine, albite, andesine, labradorite, anorthite, muscovite, cristoballite, tridymite, quartz, kyanite, mullite and orthoferrosilite. Less amounts of organic materials, carbonate and soluble salt contents were found in the samples. The clay minerals found in the samples are halloysite, illite, kaolinite, montmorrillonite and saponite.The penetration of clay minerals to the stone structure, forming a weathering zone with the presence of clay in the cracks was determined with SEM analysis. The weathering zones of the stones range between 1 cm and 2.4 cm from the exterior surface. When the average seasonal values for the environment are examined, the weathering effect of the clays after excavation of stones generally occurs in winter months due to low temperature and high humidity values.Master Thesis Fabrication and Characterizarion of Superconductor Ybco Josephson Junctions(Izmir Institute of Technology, 2008) Algül, Berrin Pınar; Abukay, Doğan; Abukay, DoğanA well-controlled, high-yield Josephson junction production process forms the basis of superconducting electronic device and circuit technology. In order to use the Josephson junctions effectively and fabricate them reproducibly, their structural and electrical characterization should be performed.This study concentrates on the fabrication and characterization of high temperature bicrystal grain boundary Josephson junctions fabricated onto 24-dand 30-degree SrTiO3 bicrystal substrates using high quality YBa2Cu3O7-. (YBCO) thin-films.200 nm thick YBCO thin films were deposited using a dc Inverted Cylindrical Magnetron Sputtering technique by investigating the thin film deposition conditions in order to obtain device quality films. The superconducting properties of the thin films were determined by electrical characterizations, consisting of resistance versus temperature and magnetic susceptibility versus temperature measurements. Structural properties were analyzed by Atomic Force Microscope, Scanning Electron Microscope and X-Ray Diffraction.Prepared thin film samples were patterned as bicrystal grain boundary Josephson junctions by standard photolithography and chemical etching processes. The current-voltage characteristics of the Josephson junctions were performed at 77 K under zero and non-zero applied field in magnetically shielded environment. The critical current values (Ic), normal resistance (Rn) and IcRn product of the output signals were determined, and the values were discussed as function of the film growth conditions. The optimization of the Josephson junctions was performed in order to improve both the signal performance and the stability of our devices against thermal cycling.Master Thesis Intrusion Detection System Alert Correlation With Operating System Level Logs(Izmir Institute of Technology, 2009) Toprak, Mustafa; Aytaç, İsmail SıtkıInternet is a global public network. More and more people are getting connected to the Internet every day to take advantage of the Internetwork connectivity. It also brings in a lot of risk on the Internet because there are both harmless and harmful users on the Internet. While an organization makes its information system available to harmless Internet users, at the same time the information is available to the malicious users as well. Most organizations deploy firewalls to protect their private network from the public network. But, no network can be hundred percent secured. This is because; the connectivity requires some kind of access to be granted on the internal systems to Internet users. The firewall provides security by allowing only specific services through it. The firewall implements defined rules to each packet reaching to its network interface. The IDS complements the firewall security by detected if someone tries to break in through the firewall or manages to break in the firewall security and tried to have access on any system in the trusted site and alerted the system administrator in case there is a breach in security. However, at present, IDSs suffer from several limitations. To address these limitations and learn network security threats, it is necessary to perform alert correlation. Alert correlation focuses on discovering various relationships between individual alerts. Intrusion alert correlation techniques correlate alerts into meaningful groups or attack scenarios for ease to understand by human analysts. In order to be sure about the alert correlation working properly, this thesis proposed to use attack scenarios by correlating alerts on the basis of prerequisites and consequences of intrusions. The architecture of the experimental environment based on the prerequisites and consequences of different types of attacks, the proposed approach correlates alerts by matching the consequence of some previous alerts and the prerequisite of some later ones with OS-level logs. As a result, the accuracy of the proposed method and its advantage demonstrated to focus on building IDS alert correlation with OS-level logs in information security systems.Master Thesis Evolution of High-Rise Buildings as Shapers of Urban Space Izmir, as a Case Study(Izmir Institute of Technology, 1999) Çelik, Zühre; Serim, Muharrem ErkalIn resent years, the construction of high-rise buildings has increased In Turkey. Unfortunately, they have been often designed without taking social, historical, environmental, symbolic and visual factors into consideration. And they have got important problems in integration with the urban space. Because the building permits are not given by based upon research and analysis. Usually, the solution at this point is to decrease the density and height limits. So they have been the most discussed issue because of the their impact on the urban environment. For these reasons, this thesis is prepared to be a guide for future research on the problems of high-rise buildings in Turkey.In this thesis context the aim is; to examine the role of high-rise buildings in the shaping of urban space and their physical, functional and social impacts on urban environment, to determine the advantages and disadvantages of high-rise buildings; and also to improve the urban planning and urban design criteria to solve the problems caused by them. This research, as a case study, attempts to evaluate existing and proposed high-rise buildings within the city context of Izmir according to their location and environmental impacts.High-rise buildings can bring great potential benefits to mankind. Instead of preventing these buildings, efforts have to be focused on maximizing its benefits. To solve the problems about high-rise buildings, it is important to consider this type of buildings in urban planning and urban design process.KEYWORDS:High-rise building, skyscraper, skyline, urban space, urban form, land mark, environmental impact, mixed use, setback, urban image, visual impact, high-rise building regulation, height control.Master Thesis Colour Design of Exterior Surfaces as an Expression of Architectural Thought(Izmir Institute of Technology, 2001) Kaynak Bayık, Ahenk; Erkarslan, ÖzlemBased on the postulation of the architectural end products communicate with the context by means of their exterior surfaces, this study claims that colour as a design concept is one of the main elements in expressing the architectural thought through out the products' surfaces. Being in a universe where human beings identify the three dimensionality with their perceptions, surface becomes one of the main concepts in identifying and communicating with the environment which they live in. The identification and communication of an object exposes itself through the way which it have been created. This exposition can be the structural and physical properties of the object where as it can be a semantic reflection of its designers' thoughts and personal expressions. The architect utilises the surfaces of the architectural end-products as a canvas in order to reflect their architectural thoughts. However, apart from the other objects, architects' canvases is three dimensional and they are two sided as inner and exterior surfaces. The architectural product's inner surface can be considered as the bordering surface of the designed space. On the other hand, the exterior surface should be considered as the inner skin of the environment.Within this thesis the components which visualises the thoughts of the designer, as the exterior facades of the building becomes the surfaces of environmental borders, these components will be studied as a part of this design process. Since colour is an important concept of the design process, it will be emphasised within its exterior surface application and its design notions. Especially, in the developing countries colour concept usually comes to the fore just as an esthetical component on the surfaces of the architectural products and can not go further than being a dye which is chosen during the last stage of the construction process. In these circumstances, colour as a surface property becomes one of the main reasons of the visual decay in the cityscapes. In this respect, this thesis does not only point out that colour is one of the main components of the design process but also indicates that colour is an inherent part of the expression of the architectural thought on the exterior surfaces of the architectural design objects which should be considered in relating with the characteristics of the environment. Keywords: Surface, Architectural Surface, Exterior Surface, Environmental Skin, Colour, Colour Perception, Functional Colour, Surface Colour, Colour in Architecture.Master Thesis Effects of Land-Ownership Transformation in Metropolitan Fringe Areas on Existing Urban Pattern (a Case Study of Ayrancılar-Torbalı)(Izmir Institute of Technology, 2000) Karataş, Neslihan; Özdemir, SemahatParallel to urbanisation, growing cities have affected their surrounding rural settlements. This effect has resulted in a structural transformation of the rural settlements in metropolitan fringe area. With this effect, the larger city grew and affected the settlements in their fringe area and with this interaction, the social, economic and physical transformations began to take placein the fringe. One of the most important phenomena, which has been affected from these interaction and transformations is the land-ownership affair. The land-ownership has an important role especially in the physical planning process. Besides affecting the physical planning process, this phenomenon is also affected by physical planning process. The alffi of the thesis is to search for the effects of land-ownership transformation in metropolitan fringe areas on existing and potential urban pattern, and to find out if there are some negative result of this mentionet interaction. In this way, new proposals can be brought up to solve the existing and potential problems related with urban land and land-ownership phenomena, and the quality of living environment can be increased. For this study, first, literature survey related to urban sprawl and urban fringe has been accomplished and land policies in Turkey have been considered. After these researches, all of the title deed data related to case study area which is Ayrancllar Municipality (plot numbers, plot sizes, plot owners, and changing of owners) have been searched between 1968-1998 in a three decades period and been transferred into maps.At the same time, a land-use survey has prepared for the area and the construction permits and physical plans have been taken from the municipality to account for three decades period. Thus, as a result of this study, it can be said that there exist a strong relationship among land-ownership transformation process, physical plan decisions, and existing and potential urban patterns and some urban problems can be solved by adopting more meaningful policies during this changing process.Master Thesis Architectural Reflections of the Political Thresholds During Interwar Years (1914-1945)(Izmir Institute of Technology, 1999) Emir, Özgür Deniz; Eyüce, ÖzenThis thesis claims that political power and ideology have the ability to transform the building forms of architecture and that power uses architecture as the ideological symbols of the regime in the interactive relationship of 'Architecture and Politics'. The study examines this relationship in Russia, Germany, Italy and Turkey which are experiencing political thresholds during the' Interwar Years' (1914-1945). The architectural reflections of political thresholds have been discussed through architectural trends, styles, built environment and urbanism. Formal and conceptual analyses and readings have been performed in order to determine the architectural transformations and variations that are parallel to political developments, architectural trends before and after the political thresholds have been analyzed comparatively. The concepts that exist similarly both in political ideologies and architectural end-products have been studied with the aim of finding the interaction between 'Architecture and Politics'. These analyses have led to a conclusion that political interference, transforms architectural trends due to its ideologies; monumentality, grandeur, axiality, symmetry order and hierarchy as a result exist in the created architectural language due to this political interference.