Flow Of Pipeline Research Articles

IBM eServer z900 high-frequency microprocessor technology, circuits, and design methodology

The IBM eServer z900 microprocessor is a seventh-generation zSeries™ (formerly S/390®) CMOS design which has achieved 1.3-GHz operation. This paper describes the 0.18-µm bulk CMOS, seven-level copper metal process and the high-frequency circuit, integration, and design methodologies developed to achieve this operation. The microprocessor was floorplanned to closely mimic the flow of the microarchitecture pipeline and reduce the communication delay overhead between units. Novel circuit techniques were used in the implementation of the arrays and cache hit detection logic to save power and reduce circuit complexity without sacrificing performance. A four-dimensional gate library and novel synthesis algorithms were developed to yield synthesized control implementations with the performance characteristics of a fully custom circuit design.

Stability of CWM in Long-distance Pipelines.

The change in apparent viscosity of CWM occurring during long-period operations was measured using a loop test facility in which a pipe of 200mm inside diameter was used. The apparent viscosity of CWM showed a tendency to increase while CWM was circulated in the loop. It was hypothesized that the agglomerated coal particles were dispersed, attributed to the high shear rates created by the CWM fluid flowing through the pipe and the pump. The coal particles in the CWM, being pulverized, adsorbed greater amount of dispersant. It was, thus, considered that the amount of dispersant in the liquid phase was reduced to an extent too little to maintain the viscosity of the CWM at low levels.For the purpose to investigate this phenomenon, the rheological properties were examined experimentally in detail at high and low shear rates. High shear rates were produced by allowing CWM to flow into a small pipe at various velocities. Low shear rates were created by a rotary viscometer. As a result, the apparent viscosity of CWM increased far more quickly at higher shear rates.Based on these findings, a model for rheological change of CWM was proposed. Increase in viscosity of CWM was predicted using this model, which exhibits the relation between shear rate and apparent viscosity. The apparent viscosities of CWM calculated by this model were in good agreement with the measured values. It became clear that an increase in apparent viscosity occurred in the flow of pipeline at low shear rates rather than during pumping operation at high shear rates. Based on this model, the required initial amount of dispersant can be determined in order to maintain the apparent viscosity of CWM almost constant.

Efficient polygon clipping for an SIMD graphics pipeline

SIMD processors have become popular architectures for multimedia. Though most of the 3D graphics pipeline can be implemented on such SIMD platforms in a straightforward manner, polygon clipping tends to cause clumsy and expensive interruptions to the SIMD pipeline. This paper describes a way to increase the efficiency of SIMD clipping without sacrificing the efficient flow of a SIMD graphics pipeline. In order to fully utilize the parallel execution units, we have developed two methods to avoid serialization of the execution stream: deferred clipping postpones polygon clipping and uses hardware assistance to buffer polygons that need to be clipped. SIMD clipping partitions the actual polygon clipping procedure between the SIMD engine and a conventional RISC processor. To increase the efficiency of SIMD clipping, we introduce the concepts of clip-plane pairs and edge batching. Clip-plane pairs allow clipping a polygon against two clip planes without introducing corner vertices. Edge batching reduces the communication and control overhead for starting of clipping on the SIMD engine.

カプセルの流体輸送に関する研究

In this paper a one-dimensional fully established annular flow analysis on a drag coefficient of the hindered-settling cylindrical capsule could be developed and compared with the results of the boundary layer theory on a drag coefficient of the freely-suspended capsuleas described before and experimental results for various factors of capsule which were falling through transparent and vertical tube filled with water.A drag coefficient could be proved hydrodynamically as follows;Cds {1-(l/2/d-1) 2} +16l (1/2/d-1)(3-1/d/2)/Rem {1n (1/2/d)(1/2/d+1)-(1/2/d+1)-(1/2/d+1)-(1/2/d-1)}d;diameter of capsuleD;diameter of piped;the capsule/pipe diameterν;kinematic viscosity of the fluidT;the capsule length/diameterRem;Reynolds number Usmd/vUsm;superficial mean velocity of the hindered-settling capsuleA drag coefficient characteristics curve obtained from the above equation could be applicable for the characteristics number 0.02<l/(1/d-1) 2Rem<0.08.

カプセルの流体輸送に関する研究

カプセルの流体輸送に関する研究