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Yayın Variable coefficient Korteweg-deVries equation in fluid-filled elastic tubes(Technical University Liberec, 2011-09-05) Demiray, HilmiIn the present work, treating the arteries as a prestressed thin elastic tube with a stenosis and the blood as an inviscid fluid, we have studied the propagation of weakly nonlinear waves in such a medium by use of the reductive perturbation method and obtained the variable coefficient Korteweg-deVries (KdV) equation as the evolution equation. A progressive wave type of solution to this evolution equation, in the sense of distribution, is presented and the result is discussed.Yayın Design of real-time VBR traffic shaping schemes by considering the impact of both buffer overflows and deadline violations(Int Inst Informatics & Systemics, 2005) Dağ, Tamer; Stavrakakis, IoannisWhile smoothing the traffic of time sensitive applications at the user premises can reduce the losses due to buffer overflows within the network, it may have an adverse effect on the losses due to the deadline violations due to the delay introduced by the smoothing process. In this paper, these loss factors are investigated and some simple metrics that capture the potential for buffer overflow and deadline violation losses under a traffic shaping scheme are introduced. Such metrics can be useful for the design of effective traffic shaping schemes that balance the adverse effects of buff-er overflow and deadline violation losses. An example of a more effective traffic shaping scheme is presented and its performance is compared to that of some more traditional schemes.Yayın Dilemma of the HR manager: An optimization for training and development budgets using integer programming a case study from an international firm(Int Inst Informatics & Systemics, 2005) Yanık, Serhat; Yazıcı, Selim; Şenel, İlhan KeremThis paper is about a dilemma of an HR manager of an international company. The major problem of HR managers is to minimize their training and development budgets. Making a training budget is not so complex; but the important, yet often neglected, part of budgeting is the costs of absence of employees. In every kind of training, whether traditional or e-learning, there is a cost for the time being spent away from work. Some of the managers think that this is an idle time for company, plus the employee is paid during this period. This paper focuses on the costs of the absence and their effect on training budgets. Some scenarios were developed with the help of an HR manager of an international firm. The feasibility of these scenarios was studied by using integer programming.Yayın IT Multisourcing in a telecommunication company(Int Business Information Management Assoc-IBIMA, 2012) Aydın, Mehmet Nafiz; Bingöl, ErdemOrganizations have used numerous sourcing strategies to lower IT costs and improve IT service levels. However, a number of these sourcing strategies have failed to deliver on their expected outcomes. Multisourcing has been advanced as a form of sourcing which addresses the deficiencies of other failed strategies. From the Telecommunication case, we found that the benefits of multisourcing IT infrastructure stem from an ability to lower IT costs, improve IT service levels and enabling access to specialist vendors for flexible capability. The costs and risks of IT multisourcing were addressed as the ongoing management of vendors and the underlying importance of a service management layer in organizations.Yayın Error propagation through generalized high dimensional model representation for data partitioning(Wiley-V C H Verlag GMBH, 2004) Tunga, Mehmet Alper; Demiralp, MetinIn many circumstances the explicit form of a multivariate function is not known; rather a finite number of data is listed from some physical experiments. In such cases a function can be constructed only by imposing some analytical structures containing a finite number of adjustable parameters to fit the function with the given values at some specified points. This means interpolation. The given data is collected or produced by some devices or means which may cause unavoidable errors. This results in an uncertainty band for each datum. The propagation of these errors through the interpolation is the focus of this work. It uses a new form of a partitioning technique called Generalized High Dimensional Model Representation (GHDMR). GHDMR is a divide-and-conquer approach starting from a constant component and proceeding upto high variate terms, univariate, bivariate and so on in the representation. The representation is truncated by keeping only constant and univariate terms for approximation. In other words just a single N variate problem is approximated by N univariate problem.Yayın Team composition and team performance: Achieving better results in an international higher education environment(Editura Niculescu, 2013-10-31) Scarlat, Cezar; Falcıoğlu, PınarIn line with former experiments, this stud), covers a period of four years (2008-2012) while teaching Project Management courses to international students at Mikkeli University of Applied Sciences, Finland - aiming to explore the possibility to apply the Belbin's theory on building successful small project teams in a multicultural higher education environment - in order to achieve better results - in terms of both satisfaction and performance. Besides exploring this possibility, the study has as objectives: (i) to assess the students' performance while working in teams; (ii) to assess the students' satisfaction of working in teams built according to different criteria; (iii) to check if there is any relationship between team members' performance and the way team is built. The influence of the cultural background was behind the scope of this work. The results are positive: the theory is applicable in the above conditions,. students' satisfaction depends on the way the team is built; building the teams according to the theory of team members' roles leads to better performance. The results of the study are important jar academic researchers as well as practitioners - higher education professors and decision makers, aiming at improving the quality of the higher education processes.Yayın The modified proactive feedback based flow control scheme for best-effort applications(International Institute of Informatics and Systemics (IIIS), 2007) Dağ, TamerHigh speed networks that are characterized by large bandwidth propagation delay products are expected to support applications with diverse traffic characteristics and Quality of Service (QoS) requirements. Thus, flow control schemes are needed for an efficient usage of the network bandwidth. A proactive feedback (PF) based flow control scheme developed by the author attempts to eliminate the bandwidth mismatch problem seen in such networks by generating and transmitting early feedbacks based on the application characteristics. In this paper, an extension of this scheme to large scale networks is presented. Due to the bottlenecked network nodes, some best effort applications may not be able to use their assigned bandwidth. For such cases, a modified version of the proactive feedback based (MPF) flow control scheme is introduced. It is observed that without affecting the other applications the best effort traffic can be significantly increased.Yayın A quasi-one-dimensional bubbly cavitating flow model and comparison with experiments(European Turbomachinery Soc-Euroturbo, 2011) Delale, Can Fuat; Başkaya, Zafer; Pasinlioğlu, Şenay; Şen, Mete; Ayder, ErkanA bubbly cavitating flow model is constructed for unsteady quasi-one-dimensional and two-dimensional nozzle flows. In each case, the system of model equations is reduced to evolution equations for the flow velocity and bubble radius and the initial and boundary value problems of the evolution equations are formulated. The rest of the flow variables are then related to the solution of the evolution equations. Nozzle flow experiments are also carried out using water. The static wall pressures are measured at different locations of the nozzle and the partial cavitation cloud cycle is recorded using a high speed camera. Results of the numerical simulations obtained for quasi-one-dimensional nozzle flows, seem to capture the measured pressure losses due to cavitation, but they turn out to be insufficient in describing the two-dimensional cavitation cloud structures, suggesting the need for two-dimensional numerical solution of the model equations.Yayın Referential interpretation of vernacular heritage in recent architectural design(Scuola Pitagore Editrice, 2015-06-11) Aslan, Emrah; Ertürk, Doğan Zafer; Ertürk, SevinçThis research is designed to look for the influences of vernacular heritage in contemporary architecture, using different design actions; imitation, bricolage, analogies, interpretation and mimesis. In order to search for the possible effect of vernacular heritage on contemporary architectural practice, seventeen cases have been analyzed with interviewing architects. The data collection method has been chosen carefully and applied in several different ways: literature review, digital documents, observations, sketches and scaled drawings; semi-structured interviews with the designer in order to catch their intentions in case studies. The result of the research showed that the Anatolian vernacular archetypes are being used by the architects in their practices via different level of referential interpretations, design actions. The research goes beyond simple subjective observations of using archetypes; this has been achieved through the development of framework for the systematic classification and analysis of a range of reference types and used both in the interpretation of visual material and in the analysis of documentary sources and interviews with architects. The intentions of each architect have been identified in case studies.Yayın Fluctuation theory of the liquid-glass transition(Trans Tech Publications Ltd, 2004) Dimitrov, Ventzislav IvanovThe glassy state and the character of the liquid-glass transition from undercooled liquid to amorphous solid is one of the biggest challenges of our time. In spite of significant progress we still cannot explain accurately the sudden solidification of undercooled liquids on the atomic scale. In the present paper we present an analytical theory of the dependence of the glass transition temperature on the rate of cooling: the glass transition temperature increases with increasing cooling rate but does not exceed some upper limit. At almost zero cooling rates (hypothetical reversible transformation of the liquid into glass) the glass transition temperature reduces to a critical temperature, similar to a phase transition temperature.
