Diamond Dicing

In OLAP, analysts often select an interesting sample of the data. For example, an analyst might focus on products bringing revenues of at least 100 000 dollars, or on shops having sales greater than 400 000 dollars. However, current systems do not allow the application of both of these thresholds simultaneously, selecting products and shops satisfying both thresholds. For such purposes, we introduce the diamond cube operator, filling a gap among existing data warehouse operations. Because of the interaction between dimensions the computation of diamond cubes is challenging. We compare and test various algorithms on large data sets of more than 100 million facts. We find that while it is possible to implement diamonds in SQL, it is inefficient. Indeed, our custom implementation can be a hundred times faster than popular database engines (including a row-store and a column-store).Comment: 29 page

Pruning Attributes From Data Cubes with Diamond Dicing

Data stored in a data warehouse are inherently multidimensional, but most data-pruning techniques (such as iceberg and top-k queries) are unidimensional. However, analysts need to issue multidimensional queries. For example, an analyst may need to select not just the most profitable stores or--separately--the most profitable products, but simultaneous sets of stores and products fulfilling some profitability constraints. To fill this need, we propose a new operator, the diamond dice. Because of the interaction between dimensions, the computation of diamonds is challenging. We present the first diamond-dicing experiments on large data sets. Experiments show that we can compute diamond cubes over fact tables containing 100 million facts in less than 35 minutes using a standard PC

Sub-diffraction thin-film sensing with planar terahertz metamaterials

Planar metamaterials have been recently proposed for thin dielectric film sensing in the terahertz frequency range. Although the thickness of the dielectric film can be very small compared with the wavelength, the required area of sensed material is still determined by the diffraction-limited spot size of the terahertz beam excitation. In this article, terahertz near-field sensing is utilized to reduce the spot size. By positioning the metamaterial sensing platform close to the sub-diffraction terahertz source, the number of excited resonators, and hence minimal film area, are significantly reduced. As an additional advantage, a reduction in the number of excited resonators decreases the inter-cell coupling strength, and consequently the resonance Q factor is remarkably increased. The experimental results show that the resonance Q factor is improved by 113%. Moreover, for a film with a thickness of \lambda/375 the minimal area can be as small as 0.2\lambda by 0.2\lambda. The success of this work provides a platform for future metamaterial-based sensors for biomolecular detection.Comment: 8 pages, 6 figure

Structure integrity analysis on nickel-diamond blade in dicing of hard-brittle ceramic die

Dicing operation in cutting hard-brittle ceramic die using nickel-diamond blade causes cracked or chipped die, accelerated tool wear and, ultimately, shortage of blade lifetime. This study aims to analyse the structural integrity of dicing blade in terms of tool wear, surface roughness, microstructure and elements during dicing. The measurements of wear blade on the blade are made by confocal microscope, whereas surface and elemental analyses are carried out with EDX SEM. Results show that the volumetric wear rate of blade is 20%, similar to roughness. The microstructure of the blade changes with occurrence of Aluminium owing to abrasive wear mechanism during cutting

POLYMER WAVEGUIDE MANUFACTURING AND PRINTED CIRCUIT BOARD INTEGRATION

In this age of ever increasing data rates in communication systems, optics are becoming more commonplace for long length (\u3e10m) signal transmission in High Performance Computing (HPC) systems due to their bandwidth capabilities which are higher than their electrical counterparts. In these optical based communication systems, Vertical Cavity Surface Emitting Lasers (VCSELs) are the most commonly used communications lasing medium for multimode fiber applications. These lasers are active in the 850 nm region, with speeds commonly at 10 Gbps/channel. VCSEL vendors are now commercializing lasers at 25 Gbps/channel as well, with research groups actively pursuing rates beyond 40 Gbps/channel, demonstrating that these communications technologies will likely be continuously incorporated in multiple generations of HPC systems. For optical based signaling technologies, fiber optics are typically utilized as the medium of choice for point to point contacts due to their low loss characteristics, stability to thermal degradation and aging, and manufacturability. Fiber optics have become a commodity, making them inexpensive. However, the high precision connection technologies required to bring light off of VSCELS and fiber to fiber are still rather expensive, limiting some of the optical applications in products. Polymer waveguides offer the promise to act as an enabling technology to provide highly complex optical routing that can be passively connected, lowering system costs and allowing next generation systems to be optically driven. For this to become a reality, polymer waveguide materials must meet multiple requirements in the communications industry. The focus of this thesis is on the understanding and optimization of the manufacturing requirements of polymer waveguide materials, their optical stability to existing standards such as Telecordia, and the impacts that printed circuit board processes have on them

Demonstration of the feasibility of automated silicon solar cell fabrication

An analysis of estimated costs indicate that for an annual output of 4,747,000 hexagonal cells (38 mm. on a side) a total factory cost of $0.866 per cell could be achieved. For cells with 14$1.22 per watt of electrical output. A laboratory model of such a facility was operated to produce a series of demonstration runs, producing hexagonal cells, 2 x 2 cm cells and 2 x 4 cm cells