Abstract. The adequacy for laboratory testing of four dolomite cores from the Culebra Dolomite of the Rustler Formation at the Waste Isolation Pilot Plant near Carlsbad, NewMexico, were evaluated using representative elementary volume (REV) theory. Gamma ray computerized tomography created three-dimensional grids of bulk density and macropore index over volumes from 1.4 x 10 -7 to 1.6 L. Three different methods for both volume averaging and REV analysis were applied and compared. Both density and macropore index converged to single values with increasing volume, which meets the most common qualitative definition of a REV. Statistical test results for the relatively homogeneous samples indicate that volumes larger than 1 to 7 mL have constant properties. Contrarily, a highly varied sample required 250 and 373 mL to achieve invariant density and macropore characteristics, respectively. Prismatic volume averaging was found to be better than slice averaging, while a qualitative test for the REV provided similar results as a rigorous statistical method. All cores were larger than the REV but were significantly different from one another. This implies that multiple cores are necessary to determine the entire range of transport properties within the rock. In practice, the concept has also been applied to characterize both nonhomogeneous porous media and large-scale properties in fractured media [Bear, 1993]. In those cases a REV was defined for both matrix and fractures. Expansion of the definition has added complications to sampling, testing, and verification procedures and has produced some debate. As Baveye and Sposito [1984] observed, while intuitively appealing, no known data had been presented to quantify the dimension and operational significance of the REV. Only recently, have Buchter et al. [1994] extrapolated limited two-dimensional porosity data to directly describe a three-dimensional REV relationship, and Clausnitzer and Hopmans [1999] presented a simple REV plot for glass beads. Thus, while almost every advanced groundwater textbook has a hypothetical plot of the REV, there is little insight on the actual shape of the REV curve, much less wisdom into how the concept may be applied.To some extent the concept of the REV has become obsolete because of the recent advances in characterization of spatial variability. We no longer expect to represent an aquifer or soil with a single value of porosity and conductivity but instead model those systems with complex stochastic representations. One may rightly ask if the REV concept holds any value beyond the narrow distinction between pore-scale processes and the bulk porous medium. To that, we answer the concept is still important in the design and interpretation of laboratory col-1199

Today's electronic devices are expected to be fully function, low power consumption and high performance. There are more and more functional modules integrated in a SoC chip. A threedimension integrated circuit (3-D IC) is developed and in which two or more layers of active electronic components are integrated both vertically into a single circuit. In two-dimension IC, the memory size usually dominated and occupied the most of area. Besides, 3-D IC designs will deal with serious challenges in design space exploration and system validation. In this work, we analyze different system architectures, mainly the architecture of the stacking memory. To demonstrate our 3-D IC design techniques, the stacking memory approach is employed in our "3D-PAC (Parallel Architecture Core)" design. In 3D-PAC, we stack 512KB SRAM directly on top of the logic die which is heterogeneous multi-core computing platform for multimedia application purpose. Finally, we use ESL technology to demonstrate the performance improvement. The result shows that there is 34.89% of speed-up by using the stacking memory architecture.

Traditional technology scaling of semiconductor chips followed Moore's Law. However, the transistor performance improvement will be limited, and designer will not see doubling of frequency every two years. Recently, three-dimension integrated circuits (3-D IC) that employ the vertically through-silicon vias (TSVs) for connecting each of dies have been proposed. It is an alternative solution to existent Package-on-Package (PoP) and System-inPackage (SiP) processes. There are many benefits by using TSVbased 3-D integration technologies: (1) more functionality can be integrated into a small silicon space for form factor reduction, (2) circuit delay can be improved by using TSVs due to the shorter interconnect and reduced parasitic capacitance/inductance, (3) different components with incompatible manufacturing process (i.e. Logic, DRAM, Flash, etc) can be combined in single 3-D IC for heterogeneous integration. In addition, there are many 3-D multi-core or many-core architectures are discussed recently. Comparing with traditional two-dimension multi-core or manycore architectures, the major difference is memory bandwidth problem can be addressed by stacked memory architecture. Intel has good demonstration through the teraflops microprocessor chip which is an 80-core design with memory-on-logic architecture. And, each core connects to a 256KB SRAM with 12GB/s bandwidth.Although 3-D stacking technology can bring us many benefits for next generation integrated circuits, it comes with many problems and challenges in system-level design. For instance, 3-D IC designs will deal with serious challenges in design space exploration and system validation. For most designs, the number of TSV will be the most critical limitation that should be considered carefully. Besides, system design by 3-D IC will become more and more complex, and it needs a full system-level solution to face the performance, number of TSV, and power issues of 3D-IC. Furthermore, it is more challenge to provide a FPGA-based prototyping system for early-stage software development.In general, the continue increasing complexity of modern SoC or embedded system design is also extreme. To achieve the required design productivity for the time-to-market pressure, a common accepted solution is using electronic system-level (ESL) design methodology to design the system in the different design abstraction level. One of the key technologies of ESL solution is to construct the HW/SW co-simulation platform by using the virtual prototyping concept. Moreover, designers need a multiphase of virtual platform construction to meet the different targets of design stage, such as early system validation and architecture exploration. In this work, we create a simulation framework by using ESL methodology to explore 3-D IC system that consists of multi-core processors with extended stacking memory.To demonstrate our 3-D IC design techniques, the stacking memory approach is employed in our "3D-PAC (Parallel Architecture Core)" design. In 3D-PAC, we stack SRAM directly on top of the...

Abstract. Tomographic images of porous media are complex distributions of linear attenuation coefficients that reflect the combined effects of scanning spatial resolution, photon statistical measurement errors, and true material densities. We address how the true voxel-scale attenuation distribution and measurement errors are convoluted to yield measured density frequency distributions. A deconvolution algorithm is demonstrated that uses the measured density frequency distributions and known photon statistical errors to quantify average cross-section volume contents of pure components and a mixedcomponent phase. The mixed-component phase represents regions where components are intertwined or varied in spaces smaller than the scanning resolution. This approach is applied to a complex core of the Culebra Dolomite Member of the Rustler Formation collected at the Waste Isolation Pilot Plant, near Carlsbad, New Mexico. The methodology provides a quantitative measure of the volume content of gypsum, dolomite, and mixedcomponents, and heterogeneity in the sample. This research demonstrates how porous media compositions can be quantified by applying a statistical approach to tomographic measurements obtained from gamma ray computerized tomography (gamma CT). More importantly, the relationship between the density frequency distribution and the component volume content and heterogeneity in a sample can be determined. These procedures are general in nature and may also be applied to X ray and synchrotron images, subject to the limitations of the specific machine and porous media system. Tomography Measurements

The three-dimensional (3-D) stacking memory is good way to extend the local memory of embedded CPU and/or DSP by the through-silicon-vias (TSVs) technology. In this work, we show a multi-core system with 3-D stacking memory, and the stacking memory can be configured as instruction cache or local data memory for each DSP core. Due to the noncacheable property of local memory, the programmers have to rethink the software algorithm and the data structure to efficiently use the extended memory space. To demonstrate the performance enhancement of 3-D system, this paper presents three enhanced multimedia applications for HW/SW cosimulation by the electronic system-level (ESL) virtual platform. According to the experimental results, the 3-D system performance can be improved by 30%~50% for assembly coded single-channel H.264 decoder and multichannel H.264 decoder respectively, compared with traditional 2-D system. In addition, for a JPEG decoder compiled with C compiler, more than 6 times system performance can be improved by placing the data section, heap and stack structure from external DDR2 memory to the 3-D stacking memory.