A 500-Mb/s quadruple data rate SDRAM interface using a skewcancellation technique

A quadruple data rate (QDR) synchronous DRAM (SDRAM) interface processing data at 500 Mb/s/pin with a 125-MHz external clock signal is presented. Since the QDR interface has a narrower data timing window, a precise skew control on data signals is required. A salient skew cancellation technique with a shared skew estimator is proposed. The skew cancellation circuit not only reduces the data signal skews on a printed circuit board down to 250 ps, but also aligns the data signals with an external clock signal. The entire interface, fabricated in a 0.35-μm CMOS technology, includes a high-speed data pattern generator and consumes 570 mW of power at 3.0-V supply. The active die area of the chip with the on-chip data pattern generator is 2.4 mm²     

New NLO-functionalized poly(1,4-phenylenevinylene) derivative containing dinitrobenzene moiety as electron acceptor

Summary New NLO-functionalized poly(1,4-phenylenevinylene) (PDNAPV) containing 2,4-dinitroanilino group, was synthesized through organic-soluble precursor pathway. The prepared polymer was characterized with NMR, FT-IR, UV-visible and other spectroscopic methods to identify its properties. The result from the thermal analyses and spectroscopic techniques showed that the precursor was converted into PDNAPV around at 200°C without any decomposition of 2,4-dinitroanilino group. The second-order NLO coefficient (χ⁽²⁾) of poled PDNAPV film was determined by second-harmonic generation technique. The resonant χ⁽²⁾ value was 26 pm/V and the resonance-corrected value (χ⁽²⁾(0)) was 12 pm/V, which was stable at room temperature for a month Received: 16 February 2001/Accepted: 13 March 2001     

Improvement of the expression level of β-glucosidase from Agrobacterium sp. in Escherichia coli by rare codon optimization

To achieve high level expression of β-glucosidase from Agrobacterium sp. (Abg) in an Escherichia coli expression system, 6 rare codons at +3, +11, +158, +308, +314, and +318 of abg gene were replaced with favored codons using site-directed mutagenesis. The rare codon replacements of +3 (CCC) and +11 (CCC) positions enhanced the expression level of Abg by 2- and 3.6-fold, respectively. The double mutant, Abg-DM, where both of +3 and +11 rare codon positions were modified showed a 5.2-fold higher expression level than the original abg gene. Circular dichroism (CD) spectra of the over-expressed Abg and original Abg enzymes were identical, indicating that Abg was properly folded during over-expression.     

Near-optimal state feedback design for singularly perturbed systems by unified approach

A near optimal state feedback design for singularly perturbed systems by a unified approach using the delta operator is presented with an example of the aircraft longitudinal motion. The main contribution of this paper is to explore the use of the i -operator that has attracted a new attention in systems science. The i -operator system unifies the continuous system and the discrete system together without loosing any characteristics of both systems. The paper offers the following; Finite-word-length-characteristics are improved using the i -operator. Floating-point-operations are reduced by block diagonalization and by time-invariant optimal feedback gain from the algebraic Riccati equation. The results of adopting those approaches are illustrated in the simulation figures and compared with the earlier one.     

Inhibitory effect of sowthistle (Ixeris dentata) on development and expression of behavioral locomotor sensitization to nicotine in rats

The aim of this study was to investigate the effects of sowthistle (Ixeris dentata, IXD) on development and expression of nicotine-induced locomotor sensitization and underlying neuronal activation reflected by c-Fos expression in rats. Rats were pretreated with IXD 30 min before a daily injection of nicotine during an 8-day development phase and then challenged with nicotine after a 6-day withdrawal period. In another set of experiments, same IXD doses were administered once 30 min before nicotine challenge. Daily IXD treatment during development phase was not effective in blocking nicotine-induced locomotor sensitization in rats. However, a single IXD treatment after the development and withdrawal periods of nicotine sensitization significantly alleviated sensitized locomotor behavior on day 15. These behavioral results were coincident with significant inhibition of nicotineinduced c-Fos expression in the nucleus accumbens. These results indicated that IXD pretreatment significantly blocked the expression, but not the development of nicotine-induced locomotor sensitization in rats.     

Image Independent Driving Power Reduction for High Frame Rate LCD Televisions

In this letter, the constant driving power reduction ratio has been achieved for column drivers regardless of the input image by incorporating a new static power reduction scheme into the previous dynamic power reduction method. The measured power reduction ratio is around 50% for a 120 Hz liquid crystal display panel in such cases of still input video and fallback.     

The influence of altruism on influenza vaccination decisions

Game theory is based on the assumption that individuals act according to self-interest and make decisions that maximize their personal payoffs. To test this fundamental assumption, we conducted a survey study in the context of influenza vaccination decisions. Contrary to the assumption of self-interest, we found that altruism plays an important role in vaccination decisions. Nevertheless, altruistic motivation has not yet been considered in epidemiological models, in predictions of vaccination decisions or in the design of vaccination policies. To determine the impact of altruism on the adherence to optimal vaccination policies and on resulting disease burden, we incorporated altruism into a game-theoretic epidemiological model of influenza vaccination. We found that altruism significantly shifted vaccination decisions away from individual self-interest and towards the community optimum, greatly reducing the total cost, morbidity and mortality for the community. Therefore, promoting altruism could be a potential strategy to improve public health outcomes.