Wiener filters in canonical coordinates for transform coding,filtering, and quantizing

Canonical correlations are used to decompose the Wiener filter into a whitening transform coder, a canonical filter, and a coloring transform decoder. The outputs of the whitening transform coder are called canonical coordinates; these are the coordinates that are reduced in rank and quantized in our finite-precision version of the Gauss-Markov theorem. Canonical correlations are, in fact, cosines of the canonical, angles between a source vector and a measurement vector. They produce new formulas for error covariance, spectral flatness, and entropy     

Knowledge maps for knowledge mining: application toR&D/technology management

Most of the world's archive of knowledge sources remains untouched by those who could greatly benefit from accessing and utilizing this information. The fundamental barriers to access and utilization by these users involve the content and format of this information. These users are not particularly interested in data compilations, research methods, and discussions of related literature. Instead, they are interested in the knowledge available from these sources in terms of concepts and principles that can enhance their planning, decision making, and allocation of resources. The article focuses on meeting these needs via a six step knowledge mining methodology that relies upon user oriented knowledge maps. This concept is illustrated in the context of R&D/technology management     

The potential of the use of dense fluids for initiating hydraulic stimulation

To improve preferentially the permeability of fractures in the deepest parts of a geothermal reservoir, a dense fluid may be injected during the very first phase of a hydraulic stimulation test. To initiate such a permeability-enhancement process in the 5000 m deep reservoir of the European Enhanced Geothermal System (EGS) project at Soultz-sous-Forêts, France, a concentrated NaCl brine was injected. The effects of this injection were estimated using measured hydraulic and microseismic data. Two tasks associated with hydraulic stimulation have been shown to be important for this purpose: (1) determination of the failure pressures of the various fractures intersecting the open-hole section under stimulation, and (2) calculation of the transient hydraulic pressure profile in the borehole.Using the numerical borehole code HEX-B, the transient pressure profiles during stimulation of wells GPK2 (June 2000) and GPK3 (May 2003) were calculated on the basis of measured wellhead data. A comparison of the temporal history of near-borehole microseismic events during the GPK2 test and downhole pressure development in the open-hole sections of this borehole indicated that use of a dense brine helped stimulate the bottom part of this well. The corresponding analysis for the GPK3 test showed that the failure pressure of the fractures in the bottom part of the wellbore was never exceeded when injecting the dense brine. We can, therefore, assume that the brine had no effect on the fractures in GPK3.     

Baselines for carbon emissions in the Indian and Chinese power sectors: Implications for international carbon trading

The study examines the dynamics of carbon emissions baselines of electricity generation in Indian states and Chinese provinces in the backdrop of ongoing electricity sector reforms in these countries. Two Indian states—Gujarat and Andhra Pradesh, and three Chinese provinces–Guangdong, Liaoning and Hubei have been chosen for detailed analysis to bring out regional variations that are not captured in aggregate country studies. The study finds that fuel mix is the main driver behind the trends exhibited by the carbon baselines in these five cases. The cases confirm that opportunities exist in the Indian and Chinese electricity sectors to lower carbon intensity mainly in the substitution of other fuels for coal and, to a lesser extent, adoption of more efficient and advanced coal-fired generation technology. Overall, the findings suggest that the electricity sectors in India and China are becoming friendlier to the global environment. Disaggregated analysis, detailed and careful industry analysis is essential to establishing a power sector carbon emissions baseline as a reference for CDM crediting. However, considering all the difficulties associated with the baseline issue, our case studies demonstrate that there is merit in examining alternate approaches that rely on more aggregated baselines.     

Methodology for Analyzing Strain States During <Emphasis Type="Italic">In Situ</Emphasis> Thermomechanical Cycling in Individual Lead-Free Solder Joints Using Synchrotron Radiation

To examine how a lead-free solder joint deforms in a thermal cycling environment, both the elastic and plastic stress and strain behavior must be understood. Methods to identify evolution of the internal strain (stress) state during thermal cycling are described. A slice of a package containing a single row of solder joints was thermally cycled from 0°C to 100°C with a period of about 1 h with concurrent acquisition of transmission Laue patterns using synchrotron radiation. These results indicated that most joints are single crystals, with some being multicrystals with no more than a few Sn grain orientations. Laue patterns were analyzed to estimate local strains in different crystal directions at different temperatures during a thermal cycle. While the strains perpendicular to various crystal planes all vary in a similar way, the magnitude of strain varies. The specimens were subsequently given several hundred additional thermal cycles and measured again to assess changes in the crystal orientations. These results show that modest changes in crystal orientations occur during thermal cycling.     

Technology standards-setting in the US wireless telecommunications industry: A study of three generations of digital standards development

This article focuses on the evolution of technology standards-setting in the US wireless telecommunications industry during the decades of the 1980s and 1990s. The purpose of this exploratory study is to understand and model the organizational process and environmental influences employed to develop three generations (i.e. second generation (2.0) Time Division Multiple Access (TDMA), second generation (2.5) Code Division Multiple Access (CDMA), and third generation (3.0) Wideband Code Division Multiple Access (WCDMA)) of de jure US wireless digital telecommunications standards. Through the use of a multi-case study approach, the research study focuses on inter-organizational strategic cooperation among wireless telecommunications firms proposing competitive technology designs in the standard development process. Based on data collected in these three case studies, wireless standard development models are “mapped” for the TDMA, CDMA and WCDMA technologies. Moreover, a generic, conceptual wireless technology standard development model is “mapped”, a further refinement of an earlier seminal model of telecommunications standard-setting. Finally, conclusions are reached, with both theoretical and practical implications, and suggested areas of future research (in the form of a set of research hypotheses) are presented.     

A low-noise fixed-tuned 300-360-GHz sub-harmonic mixer using planar Schottky diodes

This letter presents the design and fabrication of a low-noise fixed-tuned 300-360-GHz sub-harmonic mixer, featuring an anti-parallel pair of planar Schottky diodes fabricated by the University of Virginia and flip-chipped onto a suspended quartz-based microstrip circuit. The mixer exhibits a double side band (DSB) equivalent noise temperature lower than 900K over 18% of bandwidth (300-360-GHz), with 2 to 4.5mW of local oscillator (LO) power. At room temperature, a minimum DSB mixer noise temperature of 700K and conversion losses of 6.3dB are measured at 330GHz.     

A novel simultaneous unipolar multispectral integrated technology approach for HgCdTe IR detectors and focal plane arrays

In the last few years Rockwell has developed a novel simultaneous unipolar multispectral integrated HgCdTe detector and focal plane array technology that is a natural and relatively straightforward derivative of our baseline double layer planar heterostructure (DLPH) molecular beam epitaxial (MBE) technology. Recently this technology was awarded a U.S. patent. This simultaneous unipolar multispectral integrated technology (SUMIT) shares the high performance characteristics of its DLPH antecedent. Two color focal plane arrays with low-10¹³ cm⁻²s⁻¹ background limited detectivity performance (BLIP D^*) have been obtained for mid-wave infrared (MWIR, 3–5 m) devices at T>130 K and for long-wave infrared (LWIR, 8–10 m) devices at T∼80 K.     

Damage thresholds at metal surfaces for short pulse IR lasers

Measurements of damage to metal surfaces induced by intense nanosecond pulses of IR radiation are reported. Single-shot damage thresholds of Cu, stainless steel, molybdenum, and aluminum surfaces have been measured for various angles of incidence and the predicted increase in damage thresholds for grazing incidence optical components have been experimentally verified for the first time at 10 μm. In addition multiple-shot damage tests have been performed and practical lifetime curves for Cu mirrors have been established. The results are compared with existing theoretical models and shown to be in general agreement.