Fabrication process for FEP piezoelectrets based on photolithographically structured thermoforming templates

Microsystem Technologies - Piezoelectrets fabricated from fluoroethylenepropylene (FEP)-foils have shown drastic increase of their piezoelectric properties during the last decade. This led to the...     

A real-time video tracking system

Object identification and tracking applications of pattern recognition at video rates is a problem of wide interest, with previous attempts limited to very simple threshold or correlation (restricted window) methods. New high-speed algorithms together with fast digital hardware have produced a system for missile and aircraft identification and tracking that possesses a degree of ``intelligence' not previously implemented in a real-time tracking system. Adaptive statistical clustering and projection-based classification algorithms are applied in real time to identify and track objects that change in appearance through complex and nonstationary background/foreground situations. Fast estimation and prediction algorithms combine linear and quadratic estimators to provide speed and sensitivity. Weights are determined to provide a measure of confidence in the data and resulting decisions. Strategies based on maximizing the probability of maintaining track are developed. This paper emphasizes the theoretical aspects of the system and discusses the techniques used to achieve real-time implementation.     

Mechanistic models of thrust force and torque in step-drilling of Al7075-T651

In the aerospace industry, burr removal is an important and expensive part of the manufacturing process. One approach to minimizing burrs is to lower the thrust force in drilling through suitable modification of the drill geometry such as the use of step drills. This paper focuses on the modeling of thrust force and torque for step drills. A mechanistic model capturing the various material removal mechanisms, i.e. oblique cutting, orthogonal cutting, and indentation, active on different sections of the step drill is developed. Subsequently, a series of experiments is conducted to calibrate and validate the model. The validation results show that the predicted thrust and torque values are in good agreement with measured values, although the torque is slightly underestimated. The validated model was further used to investigate the effects of step drill geometry parameters on the thrust force and torque. The model predictions suggest that the thrust force increases and the torque decreases for larger secondary point angles and inner diameters.     

Omega-3 PUFA of marine origin limit diet-induced obesity in mice by reducing cellularity of adipose tissue

Omega-3 PUFA of marine origin reduce adiposity in animals fed a high-fat diet. Our aim was to learn whether EPA and DHA could limit development of obesity and reduce cellularity of adipose tissue and whether other dietary FA could influence the effect of EPA/DHA. Weight gain induced by composite high-fat diet in C57BL/6J mice was limited when the content of EPA/DHA was increased from 1 to 12% (wt/wt) of dietary lipids. Accumulation of adipose tissue was reduced, especially of the epididymal fat. Low ratio of EPA to DHA promoted the effect. A higher dose of EPA/DHA was required to reduce adiposity when admixed to diets that did not promote obesity, the semisynthetic high-fat diets rich in EFA, either α-linolenic acid (ALA, 18∶3 n−3, the precursor of EPA and DHA) or linoleic (18∶2 n−6) acid. Quantification of adipose tissue DNA revealed that except for the diet rich in ALA the reduction of epididymal fat was associated with 34–50% depression of tissue cellularity, similar to the 30% caloric restriction in the case of the high-fat composite diet. Changes in plasma markers and adipose gene expression indicated improvement of lipid and glucose metabolism due to EPA/DHA even in the context of the diet rich in ALA. Our results document augmentation of the antiadipogenic effect of EPA/DHA during development of obesity and suggest that EPA/DHA could reduce accumulation of body fat by limiting both hypertrophy and hyperplasia of fat cells. Increased dietary intake of EPA/DHA may be beneficial regardless of the ALA intake.     

Power-conscious design of the Cell processor's synergistic processor element

The authors describe the low-power design of the synergistic processor element (SPE) of the cell processor developed by Sony, Toshiba and IBM. CMOS static gates implement most of the logic, and dynamic circuits are used in critical areas. Tight coupling of the instruction set architecture, microarchitecture, and physical implementation achieves a compact, power-efficient design.     

A Resonant Global Clock Distribution for the Cell Broadband Engine Processor

Resonant clock distributions have the potential to save power by recycling energy from cycle-to-cycle while at the same time improving performance by reducing the clock distribution latency and filtering out non-periodic noise. While these features have been successfully demonstrated in several small-scale experiments, there remained a number of concerns about whether these techniques would scale to a product application. By modifying the Cell broadband engine processor to incorporate a large resonant global clock network, power savings with full functionality is demonstrated over a 20% range in clock frequencies, and a 6-8 Watt power savings at 4 GHz. This was achieved by changing one wiring level and adding an additional thick copper level to create inductors and capacitors.     

Feature space mapping for sensor fusion

In the context of a random process scene environment model, a method is presented for fusing data from multiple sensors into a simplified, ordered space for performing electronic vision tasks. The method is based on a new discriminating measure called the tie statistic that is introduced to quantify sensor/feature performance and to provide a mapping from sensor/feature measurement space to a simplified and ordered decision space. The mapping process uses the tie statistic to measure the closeness of an unknown sample probability density function (pdf) to a known pdf for a decision class. Theorems presented in this article relate the tie statistic to minimum probability of error decision making and to the well known Kolmogorov-Smirnov distance. As examples of the sensor/feature fusion method, the tie mapping process is applied to the object location (cueing) and the texture recognition problems.     

Fibroblast Growth Factor-21 and the Beneficial Effects of Long-Chain n-3 Polyunsaturated Fatty Acids

Long‐chain n‐3 polyunsaturated fatty acids (LC n‐3 PUFA) in the diet protect against insulin resistance and obesity. Fibroblast growth factor‐21 (Fgf21) is a hormonal factor released mainly by the liver that has powerful anti‐diabetic effects. Here, we tested whether the beneficial metabolic effects of LC n‐3 PUFA involve the induction of Fgf21. C57BL/6 J mice were exposed to an obesogenic, corn‐oil‐based, high‐fat diet (cHF), or a diet in which corn oil was replaced with a fish‐derived LC n‐3 PUFA concentrate (cHF + F) using two experimental settings: short‐term (3 weeks) and long‐term treatment (8 weeks). CHF + F reduced body weight gain, insulinemia, and triglyceridemia compared to cHF. cHF increased plasma Fgf21 levels and hepatic Fgf21 gene expression compared with controls, but these effects were less pronounced or absent in cHF + F‐fed mice. In contrast, hepatic expression of peroxisome proliferator‐activated receptor (PPAR)‐α target genes were more strongly induced by cHF + F than cHF, especially in the short‐term treatment setting. The expression of genes encoding Fgf21, its receptors, and Fgf21 targets was unaltered by short‐term LC n‐3 PUFA treatment, with the exception of Ucp1 (uncoupling protein 1) and adiponectin genes, which were specifically up‐regulated in white fat. In the long‐term treatment setting, the expression of Fgf21 target genes and receptors was not differentially affected by LC n‐3 PUFA. Collectively, our findings indicate that increased Fgf21 levels do not appear to be a major mechanism through which LC n‐3 PUFA ameliorates high‐fat‐diet‐associated metabolic disorders.     

The microarchitecture of the synergistic processor for a cell processor

This paper describes an 11 FO4 streaming data processor in the IBM 90-nm SOI-low-k process. The dual-issue, four-way SIMD processor emphasizes achievable performance per area and power. Software controls most aspects of data movement and instruction flow to improve memory system performance and core performance density. The design minimizes instruction latency while providing for fine grain clock control to reduce power.     

The Hector distributed run-time environment

Harnessing the computational capabilities of a network of workstations promises to off-load work from overloaded supercomputers onto largely idle resources overnight. Several capabilities are needed to do this, including support for an architecture-independent parallel programming environment, task migration, automatic resource allocation, and fault tolerance. The Hector distributed run-time environment is designed to present these capabilities transparently to programmers. MPI programs can be run under this environment on homogeneous clusters with no modifications to their source code needed. The design of Hector, its internal structure, and several benchmarks and tests are presented