While FPGA interconnect networks were originally designed to connect logic block output pins to input pins, FPGA users and architects sometimes become motivated to create connections between pins and specific wires in the interconnect. These pin-to-wire connections are motivated by both a desire to employ routing-by-abutment, in modular, pre-laid out systems, and to make direct use of resources in the fabric itself. The goal of this work is to measure the difficulty of forming such pin-to-wire connections. We show that compared to a flat placement of the complete system, the routed wirelength and critical path delay increase by 6% and 15% respectively, and the router effort increases 3.5 times. We show that while pin-to-wire connections impose increased stress on the router, they can be used under some circumstances. We also measure the impact of increasing routing architecture flexibility on these results, and propose a low-cost enhancement to improve pin-to-wire routing.

Advancements in electronic performance lead to a decrease in device size and an increase in power density. Because of these changes, current cooling mechanisms for electronic devices are beginning to be ineffective. Microchannels, with their large heat transfer surface area to volume ratio, cooled with either gas or liquid coolant, have shown some potential in adequately maintaining a safe surface temperature. By modifying the walls of the microchannel with fins, the cooling performance can be improved. Using computational fluid dynamics software, microfins placed in a staggered array on the bottom surface of a rectangular minichannel are modeled in order to optimize microstructure geometry and maximize heat transfer dissipation through convection from a heated surface. Fin geometry, dimensions, spacing, height, and material are analyzed. Correlations describing the Nusselt number and the Darcy friction factor are obtained and compared to recent studies. These correlations only apply to short fins in the laminar regime. Triangular fins with larger fin height, smaller fin width, and spacing double the fin width maximizes the number of fins in each row and yields better thermal performance. Once the effects of microfins were found, an experiment with multi-walled carbon nanotubes (MWNTs) grown on the surface were tested using both water and Al2O3/H2O nanofluid as the working medium. Minichannel devices containing two different MWNT structures – one fully coated surface of MWNTs and the other with a circular staggered fin array of MWNTs - were tested and compared to a minichannel device with no MWNTs. It was observed that the sedimentation of Al2O3 nanoparticles on a channel surface with no MWNTs increases the surface roughness and the thermal performance. Finally, using the lattice Boltzmann method, a two dimensional channel with suspended particles is modeled in order to get an accurate characterization of the fluid/particle motion in nanofluid. Using the analysis based on an ideal fin, approximate results for nanofluids with increase surface roughness was obtained. Microchannels have proven to be effective cooling systems and understanding how to achieve the maximum performance is vital for the innovation of electronics. Implementation of these modified channel devices can allow for longer lasting electronic systems.

Microchannels have been studied extensively for electronic cooling applications ever since they were found to be effective in removing high heat flux from small areas. The rate of heat removed using microchannels depends on many factors including the geometry shape, solid and fluid materials used, and surface roughness, among others. Many configurations of microchannels have been studied with various materials and compared for their effectiveness in heat removal. However, there is little research done so far in using Phase Change Material (PCM) fluids and pin fins in microchannels to enhance the heat transfer. PCM fluids exhibit greater heat transfer when the phase change material undergoes liquid-to-solid transformation. Staggered pins in microchannels have also shown higher heat removal characteristics because of the continuous breaking and formation of the thermal and hydrodynamic boundary layer; they also exhibit higher pressure drop because pins act as flow obstructers. This paper presents numerical results of circular, square, straight rectangular microchannels with various aspect ratios (1:2, 1:4 and 1:8), and rectangular microchannels with two characteristic staggered pins (square and circular, fixed height with no variation in aspect ratio). The heat transfer performance of a single phase fluid and PCM fluid in all of these microchannels and the corresponding pressure drop characteristics are also presented. An effective specific heat capacity model was used to account for the phase change process of PCM fluid. Comparison of heat transfer characteristics of single phase fluid and PCM fluid are presented for all the geometries considered. Among the straight microchannels, 1:8 geometry was found to have the highest Nusselt number. The use of PCM fluid in straight microchannels increased the Nusselt number by 3-7 percent compared to the single phase fluids. Among the staggered pin microchannels, circular pins were found to be more effective in terms of heat transfer by exhibiting higher Nusselt number. Circular pin microchannels were also found to have lower pressure drop compared to the square pin microchannels. Overall, for all the geometries considered, it was found that the PCM fluid enhances the heat transfer compared to the SPF fluid.

The purpose of this paper is to explore the information content in a trading, confirm the relationship between information-trading probability (PIN) and asset returns, and apply PIN to construct an investing strategy on a point of uninformed trader¡¦s view. I develop a decision marking model about trading decision between under order-driven market which is combined on the decision tree of the concept of D. Easley et al. (1997) and Merton (1976) jump diffusion model for modifying the PIN model to apply to order-driven market. As a result, the daily PIN were positive relatively with return, and the investing strategy which was based my model could make profit significantly in the sample period at TWSE in 2003, this investing strategy can earn profit in down and up market condition both. This result supports that hedging against information asymmetric risk is potential.

Magnetic confinement fusion has the potential to provide a nearly inexhaustible source of energy. Current fusion energy research projects involve conceptual "Tokamak" reactors, inside of which contaminants are "diverted" along magnetic field lines onto collection surfaces called divertor plates. Approximately 15% of the reactor's thermal power is focused on the divertor plates, creating a need for an effective cooling mechanism. Current extrapolations suggest that divertor plates will need to withstand heat fluxes of more than 10 MW/m2. The cooling mechanism will need to use a coolant compatible with the blanket system; currently helium, and use a minimal fraction of the reactor's available pumping power; ie: will need to experience minimal pressure drops. A leading cooling concept is the Helium Cooled Flat Plate Divertor (HCFP). This thesis experimentally examines four variations of the HCFP. The objectives are to: 1. Experimentally determine the thermal performance of the HCFP with a hexagonal pin-fin array in the gap between the impinging jet and the cooled surface over a range of flow rates and incident heat fluxes; 2. Experimentally measure the pressure drop associated with the hexagonal pin-fin array over a range of flow conditions; 3. Determine and compare the thermal performance of and pressure drop associated with the HCFP for two different slot widths, 0.5 mm and 2 mm over a range of flow rates and incident heat fluxes; 4. Compare the performance of the HCFP with a hexagonal pin-fin array with that of the HCFP with a metal-foam insert and the original HCFP; 5. Provide an experimental data set which can be used to validate numerical models of the HCFP design and its variants. 6. Analytically determine the maximum heat flux which the HCFP can be expected to withstand at theoretical operating conditions in the original and pin-fin array configurations.

Thèse de doctorat : Génie électrique : Villeurbanne, INSA : 2002. / Titre provenant de l'écran-titre. Bibliogr. p.143-146.

Thèse doctorat : Génie Electrique : Villeurbanne, INSA : 2007. Thèse doctorat : Génie Electrique : Faculté des Sciences de Monastir : 2007. / Thèse soutenue en co-tutelle. Titre provenant de l'écran-titre. Bibliogr. p. 158-164.

Thèse doctorat : Electronique. Dispositifs de l'Electronique Intégrée : Villeurbanne, INSA : 2007. / Titre provenant de l'écran-titre. Bibliogr. p. 115-119.

Thesis (Ph. D.)--Rutgers University, 2008. / "Graduate Program in Entomology." Includes bibliographical references (p. 132-139).

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