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Yayın Evolving strategies for web crawler(Işık Üniversitesi, 2009-05-06) Küçük, Kamil; Perdahçı, Nazım Ziya; Işık Üniversitesi, Fen Bilimleri Enstitüsü, Enformasyon Teknolojileri Yüksek Lisans ProgramıWith the rapid growth of Internet and Internet-based information, it becomes the largest and publicly accessible data source in the world. Every day millions of information available so to achieve information becomes harder. To get the correct information trusted web sites and search engines are used. Trusted web sites have links between themselves, and users can reach correct and relevant information. Search engines are using crawler to follow links between pages. The context available to such crawlers can guide the navigation of links with the goal of efficiently locating highly relevant target pages. Crawler takes seed pages from search engines and follows these links using multi-agents. After first search, the results are inserted to database and they are used for seed pages for another search. The aim is the get access more reliable information using more seed pages in a short time.Yayın Cluster based sensors scheduling in a target tracking application with particle filter method(Işık Üniversitesi, 2006) Özfidan, Özgür; Bayazıt, Uluğ; Işık Üniversitesi, Fen Bilimleri Enstitüsü, Elektronik Mühendisliği Yüksek Lisans ProgramıIn multisensor applications, management of sensors is neccessary for the classification of data they produce and for the efficient use of sensors as well. One of the most important aspects in sensor management is the sensor scheduling. By scheduling the sensors, serious redictions can be achieved in the cost of bandwith, power and computation. In this thesis, a simple solution for the problem of sensor scheduling in a multi-sensor target tracking application is presented. Proposed method is called sensor grouping. Due to non-linearity and non-gaussianity of the problem itself, proposed solution is presented in the framework of non-linear Bayesian Estimation. For this purpose a detailedtheoretical background of the theory of Bayesian Tracking and Particle Filtering algorithm is given.Yayın Data access layer code generator(Işık Üniversitesi, 2006) Küçükeren, Gökçe; Kuru, Selahattin; Işık Üniversitesi, Fen Bilimleri Enstitüsü, Bilgisayar Mühendisliği Yüksek Lisans ProgramıLayering techniques are commonly used in order to supply the operational requirements of today's complex enterprise applications. The codes developed for the Data Access Layer (DAL), which is the foundation of most layered applications, increases the time of projects' development phases, and the bugs in these manually written codes makes the data access unreliable. In this thesis, a tool is developed to generate the required codes for DAL. The automatically generated codes using this tool, Data Access Layer Code Generator, decreases the time wasted for DAL development and makes the data access reliable due to their uniform structure. Data Access Layer Code Generator is able to build the foundation of the layered architectures with its user-friendly interfaces integrated on the development platform and with the functionalities provided to the developers.Yayın Relations of 1994 and 2000 crises and their effects in Turkish capital markets(Işık Üniversitesi, 2002) Soykut Sarıca, Yeşim Pınar; Dew, James Kurt; Işık Üniversitesi, Sosyal Bilimler Enstitüsü, Yöneticiler İçin İşletme Yönetimi Yüksek Lisans ProgramıTurkey, one of the most rapidly growing emerging market, is a heaven for investors with young population, dynamic private sector, and liberalised financial markets. In this respect, the question of "Why does the Turkish economy always face with either a crisis or a program for guiding her out of a crisis?", comes to minds. In the analysis period of this research, the Turkish economy has experienced with two major crisis in 1994 and 2000, which are called as "balance of payment crisis". In the period, before 1994 crisis had happened, although the tight monetary and fiscal policies were supposed to be implemented, neither of them were successfully executed. In the final crisis, Turkey launched a comprehensive and consistent disinflation program at the beginning of 2000 in order to stabilise the economy, which resulted as the abondenment of the crawling peg exchange rate regime- the anchor of the International Monetary Fund (IMF)- drawn back the economic reform program, brought instant and massive market devaluation, souring inflation, and tumbling financial markets. Today, Turkish government aim is to keep the window of Turkey open to all investors and widen it enough to ensure that the government meets its borrowing requirements, banks make profit in subsidising the government while the rest of the economy continues to function with reasonable rates on loans and attractive interest on deposits in order to proper functioning of the economy. This research makes a brief survey on the relationship between financial system, particularly in capital markets and economic crisis, in order to give a general background for the role of capital market in the case of Turkey by taking main macroeconomic indicators as the leading variables and their effects on ISE as the coincidental. In the first part of the research, the emerging history of Turkish Republic is viewed for making clear the path, which Turkey followed as a developing country. In addition, the development of financial markets in Turkey is historically reviewed. After this introductory information, the effects of the deregulation and industrialisation are discussed. The discussion reflects the impacts of liberalisation upon the Turkish economy and financial markets. In the second part of this research, 1994 crisis is explained, the most severe crisis ever lived in Turkey of all times. This part continues with the chronology of the 1994 crisis and is followed by economic indicators in terms of results of the economic crisis. In the third part of this research, Turkey's problems remained the same including the high inflation rate. Turkish economy was launched a comprehensive and consistent disinflation program again. This part is followed by January 2000 and February 2001 crisis, which became as the most severe and destructive crisis ever lived in Republic of Turkey's history, worse than 1994 crisis, and resulted as another burden on Turkish economy. In the fourth part of this research, Turkish Capital Markets' development is reviewed particularly and ISE is considered for the assessment of the role of the development of Turkish Capital Markets. Current part is followed by the condition of ISE during the period 1994 through 2000, including movements in the size and the volume of market with major events of daily market environment. In the last part of this research, both crises are examined by using the financial instruments' returns in comparison with the ISE, the most efficient capital market of Turkey. Interest rates, T-Bill, foreign exchange market, money supply, and industrial production monthly returns are considered for plotting the analysis successfully on the ISE. In addition, for determining the relation between the ISE and other variables one-by-one, each of these returns are graphed. According to the results of graphs, the relation between 1994 and 2000 crises are brought into open and the reasons for 2000 crisis' getting longer than 1994 crisis are tried to be achieved. Relevant data and information have been obtained from several books and public sources such as company document press releases' annual reports, governments' statistics, databases, especially Proquest, and finally state's official web-sites and organisations' web-sites for periodic data which has been cross checked and correlated with statistics issued by the several organisations. Finally, it should be noted that, the capital markets is the most important arm of financial sector for Turkey. The future of capital markets in Turkey are highly interrelated with the stabilisation and the development in the entire economy. A better comprehension of the economic development and stabilisation package after the crisis helped public to understand the vital importance of entire capital markets.Yayın Eurasip journal on wireless commuication and networking: Editorial(Springer International Publishing, 2005-04-15) Panayırcı, Erdal; Georghiades, Costas N.; Wang, Xinheng; Çırpan, Hakan Ali[No abstract available]Yayın New criteria for the existence of stable equilibrium points in nonsymmetric cellular neural networks(2003) Özcan, Neyir; Arık, Sabri; Tavşanoğlu, Ahmet VedatThis paper presents new criteria for the existence of stable equilibrium points in the total saturation region for cellular neural networks (CNNs). It is shown that the results obtained can be used to derive some complete stability conditions for some special classes of CNNs such as positive cell-linking CNNs, opposite-sign CNNs and dominant-template CNNs. Our results are also compared with the previous results derived in the literature for the existence of stable equilibrium points for CNNs.Yayın Relative effects of marketing effectiveness dimensions on firm performance: An empirical analysis with a multi-industry sample(Bogazici Universitesi, 2009) Gül, Mısra ÇağlaThe aim of this study is to understand the influence of marketing operational efficiency and marketing system effectiveness on firm performance dimensions. Marketing operational efficiency and marketing system effectiveness are two dimensions of marketing effectiveness derived as a result of the exploratory factor analysis performed on the data. Firm performance dimensions used in the study are overall performance, ROI, percentage of new product sales, change in market share, and sales growth, all measured relative to competitors. Multiple respondent firm level data are collected through a survey of 74 firms operating in a variety of industries, resulting in 296 individual surveys. Findings indicate that marketing operational efficiency, a set of short-term, operational dimensions, positively influences all of the firm performance dimensions. On the other hand, marketing system effectiveness, measuring longer-term, strategic factors, does not have such an impact.Yayın Maximum likelihood blind channel estimation for space-time coding systems(Hindawi Publishing Corporation, 2002-05) Çırpan, Hakan Ali; Panayırcı, Erdal; Çekli, ErdinçSophisticated signal processing techniques have to be developed for capacity enhancement of future wireless communication systems, In recent years, space-time coding is proposed to provide significant capacity gains over the traditional communication systems in fading wireless channels. Space-time codes are obtained by combining channel coding, modulation, transmit diversity, and optional receive diversity in order to provide diversity at the receiver and coding gain without sacrificing the bandwidth. In this paper, we consider the problem of blind estimation of space-time coded signals along with the channel parameters. Both conditional and unconditional maximum likelihood approaches are developed and iterative solutions are proposed. The conditional maximum likelihood algorithm is based on iterative least squares with projection whereas the unconditional maximum likelihood approach is developed by means of finite state Markov process modelling. The performance analysis issues of the proposed methods are studied. Finally, some simulation results are presented.Yayın Data collection and analysis on vanet(Işık Üniversitesi, 2009-02-01) Karatoy, Hilal; Solak, Ercan; Işık Üniversitesi, Fen Bilimleri Enstitüsü, Bilgisayar Mühendisliği Yüksek Lisans ProgramıThe communication between devices is provided by wireless networks and it is growing rapidly, dependent on the needs. Wireless networks strike the attention of people throughout the world, and the ad hoc network is part of this attention. Ad hoc networks do not need structural mechanisms and are mostly used by the mobile nodes. In ad hoc networks the nodes act as a router and communicate with the other nodes. Ad hoc networks can be used in various places such as campus, shopping centers, buildings and vehicles. Ad hoc network systems without any infrastructure have two kinds of nodes which are mobile and fixed. Actually, node mobility is not taken into account. The aim of this thesis is to find the cheapest way to provide the practical statistical data that will be saved after communication between vehicles depend on road constructing, renewing, development and time schedule of the drivers etc. The data used in the analysis were the route and schedule information of the local city buses. Istanbul Metropolitan Municipality provided the coordinates of the bus stops and time tables for the data collection part. We used MATLAB to edit the data in data analysis part. We used 802.11 standards for the communication of the buses and C++ to create the protocol of data transmission. We wrote Google Earth scripts to observe the data correctness and coded TCL scripts for simulation in NS2 to see and analyze the data transfer between nodes, i.e., the buses. Different ranges of communication are used and analyzed, and their results are shown in this project. To collect more data, thousands of nodes are used, which represent more than 40 bus lines and their paths from different continents including Asia and Europe, which constitute the two sides of Istanbul.Yayın Weighted bipartite crossing minimization applications on biclustering and graph unions(Işık Üniversitesi, 2009-02-03) Sözdinler, Melih; Erten, Cesim; Işık Üniversitesi, Fen Bilimleri Enstitüsü, Bilgisayar Mühendisliği Yüksek Lisans ProgramıBiclustering gene expression data is the problem of extracting submatrices of genes and conditions exhibiting significant correlation across both the rows and the columns of a data matrix of expression values. We provide a method, LEB (Localize-and-Extract Biclusters) which reduces the search space in to local neighborhoods within the matrix by first localizing correlated structures. The localization procedure takes its roots from effective use of graph-theoretical methods applied to problems exhibiting a similar structure to that of biblustering. Once interesting structures are localized the search space reduces to small neighborhoods and the biclusters are extracted from these localities. we evaluate the effectiveness of our method with extensive experiments both using artificial and real datasets. Finally, We also used our crossing minimization heuristics for graph visualization in a layered fashion.
