Now showing items 1-20 of 196

  • Attitudes towards knowledge management in Turkish companies 

    Authors:Üçdal, Erol; Güzey, Yildiz Y.
    Publisher and Date:(2002)
    Attitudes towards knowledge management in Turkish companies are discussed. More and more companies in Turkish economy are allocating responsibility and a budget for knowledge management. Analysis show that the acts of successful knowledge management strategies brings new types of working giving people the chance to invest in knowledge maintaining the culture change and rewarding employees with new incentive schemes.

  • Trust confidence and e-commerce in cyberspace 

    Authors:Güzey, Yildiz Y.
    Publisher and Date:(2002)
    The trust confidence and e-commerce issues in cyberspace are discussed. Development of commercial activities in the cyberspace hinges on assuring consumers and businesses that their use of network services were safe secure and reliable. E-commerce requires trust across the spectrum of users and providers of services and goods. The cyberspace will never be completely secure reliable trustworthy and involves a calculated risk.

  • Branch outage solution using particle swarm optimization 

    Authors:Ceylan, Oǧuzhan; Ozdemir, Aydogan; Daǧ, Hasan
    Publisher and Date:(2008)
    For post outage MW line flows and voltage magnitude calculations most of the methods use linear methods because of their simplicity. Especially for reactive power flow calculations one can face high errors. In this paper we use a minimization method that minimizes the errors resulting from the linear system model implementation. We solve the optimization problem using particle swarm optimization. We give some outage examples using IEEE 14 bus IEEE 30 bus and IEEE 57 bus data and compare the results ...

  • An analysis of the unemployment selected MENA countries and Turkey 

    Authors:Bilgin, Mehmet Hüseyin; Kilicarslan, Ismihan N, I. N.
    Publisher and Date:(2008)
    One of the most important economic and social problems of the Middle East and North Africa (MENA) is the high rate of unemployment. Unemployment in the selected MENA countries like Egypt Israel Jordan and Turkey are examined as well as the relationship between growth and unemployment. For this reason active labor market policies should be designed to address job creation in addition to structural reform in labor markets.

  • On-line transient stability assessment using Matlab parallel programming environment 

    Authors:Soykan, Gürkan; Daǧ, Hasan
    Publisher and Date:(IEEE, 2009)
    Transient Stability Assessment (TSA) is the major part of Dynamic Security Assessment (DSA) in an electric power system. On-line TSA has gained more importance for power system security in last two decades. The decreasing costs of hardware and advanced package programs and techniques encourage researchers to apply parallel programming to the problems that are either too much time consuming or impossible to solve using serial computers. The real-time evaluation of TSA is now almost possible thanks ...

  • Parallel implementation of iterative rational Krylov methods for model order reduction 

    Authors:Yetkin, Emrullah Fatih; Daǧ, Hasan
    Publisher and Date:(IEEE, 2009)
    Model order reduction (MOR) techniques are getting more important in large scale computational tasks like large scale electronic circuit simulations. In this paper we present some experimental work on multiprocessor systems for rational Krylov methods. These methods require huge memory and computational power especially in large scale simulations. Therefore these methods are fairly suitable for parallel computing. ©2009 IEEE.

  • International financial crises and the political economy of financial reforms in Turkey: 1994-2009 

    Authors:Şakar, Birgül
    Publisher and Date:(2009)
    This study1 holds for the formation of international financial crisis and political factors for economic crisis in Turkey are evaluated in chronological order. The international arena and relevant studies conducted in Turkey work in the literature are assessed. The main purpose of the study is to hold the linkage between the crises and political stability in Turkey in details and to examine the position of Turkey in this regard. The introduction part follows the literature survey on the models ...

  • Parallel contingency analysis using differential evolution based solution for branch outage problem 

    Authors:Ceylan, Oǧuzhan; Daǧ, Hasan; Ozdemir, Aydogan
    Publisher and Date:(IEEE, 2009)
    Contingency analysis is one of the most fundamental work an electricity management center operator has to perform regularly. If both bus voltage magnitudes and reactive power flowing on the branches during any type of outages are within the acceptable limits the system is called secure. In this paper we solve the contingency problem using a recently developed local constrained optimization based branch outage problem. The optimization problem resulted from the formulation of branch outage is solved ...

  • Towards faster branch outage simulations using simulated annealing and parallel programming 

    Authors:Ceylan, Oǧuzhan; Ozdemir, Aydogan; Daǧ, Hasan
    Publisher and Date:(IEEE, 2009)
    Contingency studies such as branch outage and generator outage are among important studies of energy management centers operations. Branch outage modeling on the other hand is one of the basic steps of post-outage state estimation of an electrical power system. Real time implementation of the problem brings the necessity of using high speed methods while providing a reasonable accuracy. This paper presents simulated annealing based solution of the branch outage event which is formulated as a local ...

  • HeteroSim: Heterogeneous simulation framework 

    In order to arrange heterogeneous simulation executions it would be useful to have simulation tools that enable easy and fast creation of simulation sessions employing real-time software components beside simulation codes. Although there have been considerable amount of research activities in simulation community the current simulation tools are not sufficiently capable to support such a cooperation between components working in real-time and simulation-time. In this paper we propose a new approach ...

  • Towards Faster Branch Outage Simulations Using Simulated Annealing and Parallel Programming 

    Authors:Ceylan, Oǧuzhan; Ozdemir, Aydogan; Daǧ, Hasan
    Publisher and Date:(IEEE, 2009)
    Contingency studies such as branch outage and generator outage are among important studies of energy management centers operations. Branch outage modeling on the other hand is one of the basic steps of post-outage state estimation of an electrical power system. Real time implementation of the problem brings the necessity of using high speed methods while providing a reasonable accuracy. This paper presents simulated annealing based solution of the branch outage event which is formulated as a local ...

  • Quality of health care and patient satisfaction: An exploratory investigation of the 5Qs model at Turkey 

    Authors:Camgöz-Akdaǧ, Hatice; Zineldin, Mosad
    Publisher and Date:(2010)
    Purpose - The aim of this research is to examine the major factors affecting patients' perception of cumulative satisfaction and to address the question whether patients in Istanbul evaluate quality of health care to be similar or different to that of the Kazakhstani Egyptian and Jordanian patients. Design/methodology/approach - A conceptual model including behavioural dimensions of patient-physician relationships and patient satisfaction has been used for approach. As the empirical research setting ...

  • A spectral divide and conquer method based preconditioner design for power flow analysis 

    Authors:Daǧ, Hasan; Yetkin, Emrullah Fatih
    Publisher and Date:(2010)
    Power system simulations most of the time require solution of a large sparse linear system. Traditional methods such as LU decomposition based direct methods are not suitable for parallelization in general. Thus Krylov subspace based iterative methods (i.e. Conjugate Gradient Generalized Minimal Residuals (GMRES)) can be used as very good alternatives compared to direct methods. On the other hand Krylov based iterative solvers need a preconditioner to accelerate the convergence process. In this ...

  • Gravitational search algorithm for post-outage bus voltage magnitude calculations 

    Authors:Ceylan, Oǧuzhan; Ozdemir, Aydogan; Daǧ, Hasan
    Publisher and Date:(2010)
    Branch outage problem is one of the key problems in power system security analysis. This paper solves branch outage problem using a bounded approach. Local constrained optimization problem in the bounded approach is solved by the gravitational search algorithm. Test results of IEEE 14 30 and 118 bus systems are compared to those of ac load flow method in terms of both accuracy and speed.

  • Harmony search method based parallel contingency analysis 

    Authors:Ceylan, Oǧuzhan; Daǧ, Hasan; Ozdemir, Aydogan
    Publisher and Date:(2010)
    Power system security management is one of the key problems in power system analysis. Power system management center operators need to simulate contingencies as fast as possible and take the remedial actions in time. These contingency analyses comprise of the outages of the branches transformers and other power system components. This paper solves branch outage problem using a bounded approach. Harmony search method is used to solve the local constrained optimization problem of the bounded approach. ...

  • Parallel Implementation Of Iterative Rational Krylov Methods For Model Order Reduction 

    Authors:Yetkin, E. Fatih; Daǧ, Hasan
    Publisher and Date:(IEEE, 2010)
    Model order reduction (MOR) techniques are getting more important in large scale computational tasks like large scale electronic circuit simulations. In this paper we present some experimental work on multiprocessor systems for rational Krylov methods. These methods require huge memory and computational power especially in large scale simulations. Therefore these methods are fairly suitable for parallel computing.

  • Applications of Eigenvalue Counting and Inclusion Theorems in Model Order Reduction 

    Authors:Yetkin, E. Fatih; Daǧ, Hasan
    Publisher and Date:(Springer-Verlag Berlin, 2010)
    We suggest a simple and an efficient iterative method based on both the Gerschgorin eigenvalue inclusion theorem and the deflation methods to compute a Reduced Order Model (ROM) to lower greatly the order of a given state space system. This method is especially efficient in symmetric state-space systems but it works for the other cases with some modifications.

  • Parallel Contingency Analysis Using Differential Evolution Based Solution For Branch Outage Problem 

    Authors:Ceylan, Oǧuzhan; Daǧ, Hasan; Ozdemir, Aydogan
    Publisher and Date:(IEEE, 2010)
    Contingency analysis is one of the most fundamental work an electricity management center operator has to perform regularly. If both bus voltage magnitudes and reactive power flowing on the branches during any type of outages are within the acceptable limits the system is called secure. In this paper we solve the contingency problem using a recently developed local constrained optimization based branch outage problem. The optimization problem resulted from the formulation of branch outage is solved ...

  • On-Line Transient Stability Assessment Using Matlab Parallel Programming Environment 

    Authors:Soykan, Gürkan; Daǧ, Hasan
    Publisher and Date:(IEEE, 2010)
    Transient Stability Assessment (TSA) is the major part of Dynamic Security Assessment (DSA) in an electric power system. On-line TSA has gained more importance for power system security in last two decades. The decreasing costs of hardware and advanced package programs and techniques encourage researchers to apply parallel programming to the problems that are either too much time consuming or impossible to solve using serial computers. The real-time evaluation of TSA is now almost possible thanks ...

  • Guidelines for IT change management shown on an example in Turkey 

    In today's highly technology driven competitive global markets the ability to adopt is the only guarantee of survival. Businesses need to show ability to enable a competitive edge by taking their products or services to markets before the competitors. Today business have to take care that IT systems are able to adapt to the changes caused by our highly technology driven society and the influences of digitalization and globalization to support the needs of businesses quickly and efficiently. The ...