高标清混合格式的广播世界

本将针对电视台从标清格式向标清与高清格式混合播出进行改造所需要考虑到的问题进行讨论。要想做到这一点就要找到满带宽基带运行模式与信号压缩模式的平衡点。     

Low-power encodings for global communication in CMOS VLSI

Technology trends and especially portable applications are adding a third dimension (power) to the previously two-dimensional (speed, area) VLSI design space. A large portion of power dissipation in high performance CMOS VLSI is due to the inherent difficulties in global communication at high rates and we propose several approaches to address the problem. These techniques can be generalized at different levels in the design process. Global communication typically involves driving large capacitive loads which inherently require significant power. However, by carefully choosing the data representation, or encoding, of these signals, the average and peak power dissipation can be minimized. Redundancy can be added in space (number of bus lines), time (number of cycles) and voltage (number of distinct amplitude levels). The proposed codes can be used on a class of terminated off-chip board-level buses with level signaling, or on tristate on-chip buses with level or transition signaling     

Analysis of dual-VT SRAM cells with full-swingsingle-ended bit line sensing for on-chip cache

This paper compares different high-V_T and dual-V_T design choices for a large on-chip cache with single-ended sensing in a 0.13 μm technology generation. The analysis shows that the best design is the one using a dual-V_T cell, with minimum channel length pass transistors, and low-V_T peripheral circuits. This dual-V_T circuit provides 20% performance gain with only 1.3× larger active leakage power, and 2.4% larger cell area compared to the best design using high-V_T cells with nonminimum channel length pass transistors     

Simulation of Concrete Paving Operations on Interstate-74

The objective of this paper was to study and optimize the concrete paving operations taking place in the reconstruction project of Interstate-74 using computer simulation. To achieve this objective, field data were collected during construction, and were then used to determine adequate probabilistic density functions for the activities’ duration and to test a developed simulation model. Upon testing, the developed model was used to study the impacts of resources on the flow of operations and on the cost effectiveness of the construction process. In general, application of simulation methods to concrete paving operations was successful and its accuracy was acceptable as compared to field measurements. Based on the results of a sensitivity analysis of the critical resources, multiple factors were considered in the decision-making process to ensure that all aspects of the operation are evaluated. This includes total operation time, productivity, costs of the operation, average truck delay, and idle times for the paver and the spreader. For the conditions pertinent to this construction site, ten trucks, one paver and one spreader, and three finishing and plastic-covering crews are recommended. Using this set of resources would result in a prompt and effective execution of the operation. Practical implementation and limitations of the developed model in similar construction operations is discussed.     

Heterogeneity and physiological activity of bovine k-casein proteolysis products

Gel chromatography in columns with Sephadex G-50 and biogel P-2 was used to separate a number of fractions formed in k-casein of cow's milk after short-term treatment with swine trypsin. These fractions, similar to beta-casomorphin, are capable of reducing the respiration and heart rates in rabbits after intravenous injection in a dose of 100 micrograms/kg, that suggests their capacity for interaction with opiate receptors. Some fractions injected subcutaneously induce in starving animals an electroencephalographic picture of satiation, similar to that observed after cholecystokinin injections. Correlation of amino acid composition and physiologic activity has evidenced that cholecystokinin and opioid effects are caused by different peptides.     

Urban spatial adjustments resulting from rising energy costs

Since the 1973 oil embargo, the cost of energy in the United States has risen dramatically. The effect on the spatial structure of cities due to higher energy cost is the subject of this paper. Within the framework of a continuous general equilibrium model, it is demonstrated that, contrary to some previous studies, cities might be expected to decentralize rather than to centralize.     

Analog VLSI for robot path planning

Analog VLSI provides a convenient and high-performance engine for robot path planning. Laplace's equation is a useful formulation of the path-planning problem; however, digital solutions are very expensive. Since high precision is not required, an analog approach is attractive. A resistive network can be used to model the robot's domain with various boundary conditions for the source, target, and obstacles. A gradient descent can then be traced through the network by comparing node voltages. We built two analog CMOS VLSI chips to investigate the feasibility of this technique. Design issues included the choice of resistive element, tessellation of the domain, programming of the network, and readout of the settled network. Both chips can be connected to a standard VME bus interface to permit their use as coprocessors in otherwise digital systems.A preliminary short version of this paper was presented at the 1992 ASILOMAR Conf. on Computers, Signals and Systems.     

Glycopeptide obtained from k-casein and its effect on protein assimilation

The products of restricted proteolysis of kappa-casein were separated by gel filtration. Intravenous injection of high- and low-molecular fractions substantially reduced the pentagastrin-stimulated acid secretion in the anesthetized rat stomach. Intermediate fractions had lesser physiological activity. One of the active fractions administered intraintestinally inhibited acid secretion and reduced the pentagastrin-stimulated secretion in rat weanling isolated stomach. All the active fractions inhibited the stimulated secretion in rats with a ligated vagus. It is concluded that the nervous system does not play a crucial role in the mechanism by which gastric acid secretion is inhibited by the products of restricted proteolysis of kappa-casein. Decreasing acid secretion in the stomach, glycopeptide provides for the conditions favouring the efficacy of protein utilization at an early age. It is suggested that the effect of glycopeptide obtained from kappa-casein on the process of assimilation is mediated via peptide hormones.     

GMH2000系统和无线本地环路

休斯网络系统公司（ＨＮＳ）的ＧＭＨ２０００固定无线系统是一个基于Ｅ－ＴＤＭＡ的系统，它为公用电话业务提供了最有效的无线本地环路的解决方案。