542 resultados para 1302
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In this paper we review recent theoretical approaches for analysing the dynamics of on-line learning in multilayer neural networks using methods adopted from statistical physics. The analysis is based on monitoring a set of macroscopic variables from which the generalisation error can be calculated. A closed set of dynamical equations for the macroscopic variables is derived analytically and solved numerically. The theoretical framework is then employed for defining optimal learning parameters and for analysing the incorporation of second order information into the learning process using natural gradient descent and matrix-momentum based methods. We will also briefly explain an extension of the original framework for analysing the case where training examples are sampled with repetition.
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This paper presents the current status of our research in mode-locked quantum-dot edge-emitting laser diodes, particularly highlighting the recent progress in spectral and temporal versatility of both monolithic and external-cavity laser configurations. Spectral versatility is demonstrated through broadband tunability and novel mode-locking regimes that involve distinct spectral bands, such as dual-wavelength mode-locking, and robust high-power wavelength bistability. Broad tunability of the pulse repetition rate is also demonstrated for an external-cavity mode-locked quantum-dot laser, revealing a nearly constant pulse peak power at different pulse repetition rates. High-energy and low-noise pulse generations are demonstrated for low-pulse repetition rates. These recent advances confirm the potential of quantum-dot lasers as versatile, compact, and low-cost sources of ultrashort pulses. © 2011 IEEE.
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Study Design. An immunohistological study of surgical specimens of human intervertebral disc.Objective.To examine the presence of pleiotrophin in diseased or damaged intervertebral disc tissue and the association between its presence and the extent of tissue vascularization and innervation.Summary of Background Data. Increased levels of pleiotrophin, a growth and differentiation factor that is active in various pathophysiologic processes, including angiogenesis, has been associated with osteoarthritic changes of human articular cartilage. The association between pleiotrophin expression and pathologic conditions of the human intervertebral disc is unknown.Methods. Specimens of human lumbar intervertebral discs, obtained following surgical discectomy, were divided into 3 groups: nondegenerated discs (n = 7), degenerated discs (n = 6), and prolapsed discs (n = 11). Serial tissue sections of each specimen were immunostained to determine the presence of pleiotrophin, blood vessels (CD34-positive endothelial cells), and nerves (neurofilament 200 kDa [NF200]-positive nerve fibers).Results. Pleiotrophin immunoreactivity was seen in disc cells, endothelial cells, and in the extracellular matrix in most specimens of intervertebral disc but was most prevalent in vascularized tissue in prolapsed discs. There was a significant correlation between the presence of pleiotrophin-positive disc cells and that of CD34-positive blood vessels. NF200-positive nerves were seen in vascularized areas of more degenerated discs, but nerves did not appear to codistribute with blood vessels or pleiotrophin positivity in prolapsed discs.Conclusions. Pleiotrophin is present in pathologic human intervertebral discs, and its prevalence and distribution suggest that it may play a role in neovascularization of diseased or damaged disc tissue.
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Mathematics Subject Classification: 26A33, 34A37.
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A dolgozat a visszutas logisztikát, az újrahasznosítást igyekszik beilleszteni a vállalati termeléstervezés keretei közé. A szükséglettervezési rendszerek (material requirements planning, MRP) célja a készletek és beszerzendő anyagok, alkatrészek időben ütemezett gyártásának és beszerzésének megtervezése. A klasszikus MRP rendszereket az utóbbi időben próbálja a tudomány az újrahasznosítással kibővíteni. Mivel ebben az esetben az új, és újrafelhasználható anyagokat külön kell nyilvántartani, ezért az MRP-táblák és készletek növekednek. A rendelési tételnagyságok meghatározása is nehezebb, összetettebb tételnagysághoz vezet. A dolgozatban egy visszutas logisztikai készletmodellt ismertetünk, valamint annak dinamikus kiterjesztését, amely alapja lehet az SAP-ba beépíthető rendelés állomány meghatározó heurisztikának. ____ The aim of the paper is to extend production planning with reverse logistics and reuse. Material requirements planning (MRP) systems plan and control invetory levels and purchasing activities of the firm. In the last decade scientists on this field try to involve reverse logistics activities in MRP systems. Size of MRP-tables is growing in this case because of the alternative use of newly purchased products and reusable old items. Determination of order quantities will be more complex with these two modes of material supplies. An EOQ-type reverse logistics model is presented in the paper with a dynamic lot size generalization. The generalized model can be seen as a basic model to build in production planning and control system like SAP.
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Suggestions for future planning are offered to Hong Kong tourism practitioners and policy makers on the basis of estimated tourism demand, 1998 to 2007. The authors give an overview of the historical background of the Hong Kong tourism industry and use formal tourism forecasting techniques to estimate this demand.
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Vol. 21, Issue 67, 12 pages
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Florida International University Commencement Ceremony December 14,2010 at US Century Bank Arena ( Session 4) Colleges graduated: College of Arts and Sciences
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This dissertation provides an analytical framework to study the political economy of policy reform in the Dominican Republic during the nineties. Based on a country study, I develop two theoretical models that replicate the mechanisms of policy approval in developing countries with weak democracies. The first model considers a pro-reform President who submits a tariff bill to an anti-reform Congress dominated by the opposition party. In between, two opposing lobbies try to get their favored policy approved. Lobbies act as Stackelberg leaders vis a vis a weak President. The behavior of the Congress is determined exogenously while the lobbies act strategically pursuing the approval of the reform bill and indirectly affecting the President's decision. I show that in such a setting external agents like the Press play an important role in the decision-making process of the political actors. The second model presents a similar framework. However, the President, who is a Stackelberg leader, is allowed only two choices, total reform or status-quo. I show how a lobby reacts to an increase in its rival's or its own size. These reactions depend on the President's level of commitment to the reform. Finally, I discuss the effect of variations in the size of the lobbies on the President's choice. The model suitably explains real events that took place in the Dominican Republic in the mid-nineties.
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http://digitalcommons.fiu.edu/fce_lter_photos/1302/thumbnail.jpg
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Approaches to quantify the organic carbon accumulation on a global scale generally do not consider the small-scale variability of sedimentary and oceanographic boundary conditions along continental margins. In this study, we present a new approach to regionalize the total organic carbon (TOC) content in surface sediments (<5 cm sediment depth). It is based on a compilation of more than 5500 single measurements from various sources. Global TOC distribution was determined by the application of a combined qualitative and quantitative-geostatistical method. Overall, 33 benthic TOC-based provinces were defined and used to process the global distribution pattern of the TOC content in surface sediments in a 1°x1° grid resolution. Regional dependencies of data points within each single province are expressed by modeled semi-variograms. Measured and estimated TOC values show good correlation, emphasizing the reasonable applicability of the method. The accumulation of organic carbon in marine surface sediments is a key parameter in the control of mineralization processes and the material exchange between the sediment and the ocean water. Our approach will help to improve global budgets of nutrient and carbon cycles.
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Acknowledgments We thank Dr Daan Velseboer for providing additional unpublished data for this review. We thank Dr Lorna Aucott for her comments on a draft of this paper. We are grateful for funding for this study from the Chief Scientist Office of the Scottish Government (Clinical Academic Fellowship CAF/12/05) and from Parkinson’s UK (Grant Number G-1302).
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Acknowledgments We thank Dr Daan Velseboer for providing additional unpublished data for this review. We thank Dr Lorna Aucott for her comments on a draft of this paper. We are grateful for funding for this study from the Chief Scientist Office of the Scottish Government (Clinical Academic Fellowship CAF/12/05) and from Parkinson’s UK (Grant Number G-1302).