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Permanent URI for this collectionhttps://hdl.handle.net/20.500.14288/3
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Publication Metadata only Syndicated lending under asymmetric creditor information - Correction(Elsevier, 1996) Cadot, O; Department of Business Administration; Banerjee, Saugata; Researcher; Department of Business Administration; College of Administrative Sciences and Economics; N/AThis paper explores how asymmetric information about borrower quality among syndicated lenders alters the incentive to refinance illiquid borrowers. We use a model in which lenders enter the market sequentially in two rounds of lending. Between the two rounds, a shock separates borrowers into good ones and bad ones, and early entrants acquire information about individual borrower type, while late entrants know only the distribution of borrower types. The asymmetric information structure gives rise to both signalling and screening issues. We show that self-selecting contracts do not exist, and that there is always a pooling Perfect Bayesian Equilibrium in which late entrants lend to both good and bad types, without borrower type being exposed before final clearing at the terminal time. Based on this framework, we argue that prior to the 1982 international debt crisis, it was possible for banks with heavy exposure to troubled debtors to attract rational newcomers in syndicated loans which were, with positive probability, bailout loans.Publication Metadata only Finite-capacity scheduling-based planning for revenue-based capacity management(Elsevier Science Bv, 1997) Department of Business Administration; Akkan, Can; Faculty Member; Department of Business Administration; College of Administrative Sciences and Economics; N/AFinite-capacity scheduling can be argued to be a crucial component of revenue-based capacity management. In that case, one way to plan production is to reserve portions of capacity for incoming customer orders as they arrive, in real-time. In such a planning method, the way these work-orders are scheduled affects the useable capacity, due to fragmentation of the time-line. Assuming the work-orders are rejected if they cannot be inserted into the existing schedule, we develop heuristics to minimise the present-value of the cost of rejecting orders and inventory holding cost due to early completion. We perform simulation experiments to compare the performance of these heuristics in addition to some common heuristics used in practice.Publication Metadata only Comparison between difference-frequency generation and parametric fluorescence in quasi-phase-matched lithium niobate stripe waveguides(IEEE, 1996) Baldi, P.; El Hadi, K.; De Micheli, M. P.; Ostrowsky, D.B.; Department of Physics; Sundheimer, Michael; Faculty Member; Department of Physics; College of Sciences; N/ATuning curves and gain are two relevant parameters for integrated optical parametric oscillators. We show in this paper that they can be determined with a good precision without building a high-finesse cavity by measurement of the optical parametric fluorescence and difference-frequency generation. In the first part of this paper, we compare theoretically the guided optical parametric fluorescence and the guided difference-Frequency generation in the quasi-phase matching configuration. In the second part, we compare experimental results on optical parametric fluorescence in the 1.2-2.2-μm region and optical difference-frequency generation from a 1.55-μm laser diode using a pump wavelength between 775-795 nm in quasi-phase-matched lithium niobate stripe waveguides. This comparison shows that the gain measured by both methods is identical, but, while parametric fluorescence allows us to obtain the quasi-phase-matching curve, the difference-frequency generation gives a simpler and more accurate measurement of the gain. The combination of these two techniques provides therefore a powerful tool for evaluating the different fabrication processes of the nonlinear waveguides, without actually fabricating a parametric oscillator.Publication Metadata only Syndicated lending under asymmetric creditor information(Elsevier, 1996) Cadot, O; Department of Business Administration; Banerjee, Saugata; Researcher; Department of Business Administration; College of Administrative Sciences and Economics; N/AThis paper explores how asymmetric information about borrower quality among syndicated lenders alters the incentive to refinance illiquid borrowers. We use a model in which lenders enter the market sequentially in two rounds of lending. Between the two rounds, a shock separates borrowers into good ones and bad ones, and early entrants acquire information about individual borrower type, while late entrants know only the distribution of borrower types. The asymmetric information structure gives rise to both signalling and screening issues. We show that self-selecting contracts do not exist, and that there is always a pooling Perfect Bayesian Equilibrium in which late entrants lend to both good and bad types, without borrower type being exposed before final clearing at the terminal time. Based on this framework, we argue that prior to the 1982 international debt crisis, it was possible for banks with heavy exposure to troubled debtors to attract rational newcomers in syndicated loans which were, with positive probability, bailout loans.Publication Metadata only A station model for continuous materials flow production systems(Taylor & Francis, 1997) Yeralan, S; Department of Business Administration; Tan, Barış; Faculty Member; Department of Business Administration; College of Administrative Sciences and Economics; 28600This study develops a station model for continuous flow production systems. The most prominent use of the model is as a building block for a general and flexible decomposition method to analyse and design continuous materials flow production systems. Station breakdown and a finite capacity buffer are considered. Station inference caused by the blocking and starving phenomena is included in the station model. We assume that the time to station breakdown and station repair are exponentially distributed while the buffer is neither empty nor full. No restrictive assumptions are made about the distributions of the station breakdown and repair times when the station is blocked or starved, that is, while the buffer remains empty or remains full. The production rate and the expected level of the buffer are given in closed form. Numerical results that show the effects of the input parameters on the production rate along with an overview of the decomposition methods are presented.Publication Metadata only Generation of controlled acoustic-waves by optimal-design of surface loads with constrained forms(Pergamon-Elsevier Science Ltd, 1995) Kim, Ys; Rabitz, H; Tadi, M; Mcmanus, Jb; Department of Mathematics; Aşkar, Attila; Faculty Member; Department of Mathematics; College of Sciences; 178822Model calculations are presented for the optimal design of surface force patterns to generate acoustic waves that come to a focus within the bulk of a homogeneous elastic solid. The optimal design consists of achieving a high level of energy at the target at a prescribed time by applying a relatively minimal surface force while aiming for a minimal system disturbance away from the focal target. Such optimal designs were derived in an earlier paper, in which no restriction was imposed on the functional form of the applied stress. In this paper we examine the importance of the fine detail in the earlier derived forcing functions in achieving efficient acoustic focusing. We repeat the optimal design calculations with the surface stress constrained to be in the form of rings of variable radius, with cross sectional profiles made by the superposition of two Gaussians. The optimality conditions are secured via the conjugate gradient algorithm (CGA) and the mechanics of the elastic medium are treated by the finite element method along with using the half space Green's function matrix. We use a criterion for focusing efficiency of the ratio of acoustic energy in the target volume to the total work done on the surface, at a prescribed time. The calculations show the high levels of focusing efficiency derived in earlier work with unconstrained force patterns also can be achieved with constrained and simplified force patterns. This observation is encouraging in terms of the robustness of the optimal solution as well as the possibility of laboratory realizations of the designed force patterns for generating focused acoustic waves.Publication Metadata only Hydrophilic polyurethaneurea membranes: influence of soft block composition on the water vapor permeation rates(Elsevier Sci Ltd, 1999) Department of Chemistry; Department of Chemistry; Yılgör, İskender; Yılgör, Emel; Faculty Member; Researcher; Department of Chemistry; College of Sciences; College of Sciences; 24181; 40527High molecular weight segmented polyurethaneurea (PUU) copolymers based on an aliphatic diisocyanate, bis(4-isocyanatocyclohexyl)methane and mixed hydrophilic and hydrophobic soft segments were prepared. Hydrophilic blocks consisted of poly(ethyleneoxide) (PEO) of molecular weight 1450 g/mol, whereas the hydrophobic blocks were poly(tetramethylene oxide) of molecular weight 2000 g/mol. Ethylene diamine was used as the chain extender. Hard segment contents of the copolymers were kept constant at 18%, whereas PEO contents were varied between 0% and 50% by weight. Water vapor permeation rates (WVPR) of thin films (23-178 mu m) cast from dimethylformamide solutions were determined. In studies performed at 23 degrees C and 50% relative humidity, the relationship between PEO content and WVPR followed an S-shaped curve. For copolymers containing up to about 15% by weight of PEG, WVPR were fairly low. This was followed by a region where WVPR increased continuously for membranes containing between 15% and 30% PEG. Further increase in PEO content above 30% did not influence the WVPR substantially. There was also a dramatic increase in WVPR with an increase in temperature from 23 degrees C to 37 degrees C. Activation energy of permeation was determined to be 91.5 kJ for PUU containing 22.0% by weight of PEG. Equilibrium water absorption levels of PUU containing different levels of PEO in their backbone structures followed a similar trend to that of WVPR. Hydrophilic PUUs showed good tensile properties and mechanical integrity even at very high levels of water absorption.Publication Metadata only Stratified partial likelihood estimation(Elsevier, 1999) Ridder, Gert; Department of Economics; Tunalı, Fehmi İnsan; Faculty Member; Department of Economics; College of Administrative Sciences and Economics; 105635When multiple durations are generated by a single unit, they may be related in a way that is not fully captured by the regressors. The omitted unit-specific variables might vary over the durations, They might also be correlated with the variables in the regression component. We propose an estimator that responds to these concerns and develop a specification test for detecting unobserved unit-specific effects, Data from Malaysia reveal that concentration of child mortality in some families is imperfectly explained by observed explanatory variables, and that failure to control for unobserved heterogeneity seriously biases the parameter estimates.Publication Metadata only Flow-line scheduling problem with controllable processing times(Taylor & Francis, 1997) Kouvelis, P.; Department of Business Administration; Karabatı, Selçuk; Faculty Member; Department of Business Administration; College of Administrative Sciences and Economics; 38819In this paper we address the simultaneous scheduling and optimal-processing-times selection problem in a multi-product deterministic flow line operated under a cyclic scheduling approach. The selection of processing times plays an important role in achieving the desired production rate with the least possible operating cost. We first formulate the important subproblem of optimal-processing-times selection for different objectives, when the sequence of jobs is fixed, and then develop an efficient solution procedure for it. The fast solution of the fixed sequence problem is necessary for the development of efficient approximate solution procedures for the simultaneous scheduling and optimal-processing-times problem. A computational study on the effectiveness of the proposed solution procedure is presented. For the solution of the simultaneous scheduling and optimal-processing-times problem we suggest an iterative solution procedure, and report our computational experience with this procedure. For the solution of large problems we present a genetic algorithm. The effectiveness of the algorithm is demonstrated through computational results and by evaluating the performance of the obtained solutions against lower bounds that we developed for the problem.Publication Metadata only Is there persistence in the growth of manufactured exports? evidence from newly industrializing countries(Elsevier, 1997) Mody, Ashoka; Department of Economics; Yılmaz, Kamil; Faculty Member; Department of Economics; College of Administrative Sciences and Economics; 6111Applying cointegration techniques in a panel data setting, we document persistent growth of manufactured exports from certain developing countries. To complement the investigation of persistence (measured by the country 'fixed-effects'), we analyze asymmetries in income elasticities: for all developing countries, the decline in exports with world income contraction is sharper than is the rise on the upswing; the decline is, however, especially pronounced for countries with low or negative persistence. The results are consistent with long-term buyer-supplier relationships that create 'insiders' and 'outsiders' in manufactured goods trading. Exports are also influenced by the transactional infrastructure (proxied by telecommunications penetration).