基于峰值调整和多缩放因子的频谱整形新技术

AMR-WB＋用了全局增益和pre／de—shaping技术调整量化数据动态范围,但这种处理方法存在无法集中调整局部频段量化质量和高频量化质量降低2个缺陷。提出了一种新的基于峰值调整和多缩放因子的频谱整形技术,该技术可克服以上2个缺陷,并给出了主观和客观评价。     

一种改进的DSSS系统的码捕获技术

针对低信噪比条件下直接序列扩频(DSSS)系统的码捕获问题,提出了差分非相干累加的PN码捕获技术。研究了差分相干与差分非相干码捕获技术的工作性能,仿真结果表明,差分非相干码捕获技术具有更强的抗载波频偏能力。在此基础上,克服调制数据对码捕获的影响,提出了一种改进的差分非相干码捕获技术,即差分非相干累加的码捕获技术。仿真研究证明了差分非相干累加码捕获技术比差分非相干码捕获技术有4 dB的改善,其更能适应低信噪比条件工作。     

Error Analysis of the Kmetz/Maenner Algorithm

Use of low-precision logarithms can minimize power consumption and increase the speed of multiply-intensive signal-processing systems, such as FIR filters. Although straight table lookup is the most obvious way to compute the logarithm, Maenner claims to have discovered a technique that produces four extra bits at no cost. We analyze Maenner's technique and show that in fact the technique provides only one extra bit of precision. A related technique by Kmetz, which has never been analyzed before, is shown here to be more accurate than Maenner's. We compare these techniques to the more complex bipartite technique, and show that Kmetz's technique takes less memory for systems requiring fewer than ten bits of precision.     

A low‐complexity companding technique using Padé approximation for PAPR reduction of an OFDM system

Orthogonal Frequency Division Multiplexing (OFDM) systems have become the most promising wireless communication systems in the recent years. For OFDM systems, there is one major drawback, which is the high peak‐to‐average power ratio (PAPR). Companding techniques have been frequently proposed to reduce PAPR. Exponential companding technique offers efficient PAPR reduction with a low bit error rate (BER). However, the exponential companding technique is difficult to implement. This paper utilizes the Padé approximation to simplify the exponential companding technique. The simulation results demonstrate that the proposed companding technique offers the same performance results as those of the exponential companding technique, while Additive White Gaussian Noise (AWGN) or multipath fading channel is considered. Further, the hardware implementation results show that the complexity of the proposed companding technique is less than that of the exponential companding technique. Copyright © 2011 John Wiley & Sons, Ltd.     

VGT turbocharger controlled by an adaptive technique

This paper provides an adaptive technique for the control of the variable geometry turbine in a turbocharged compression ignition engine. The adaptive control is based on a one-step-ahead (OSA) technique and a least-square parameter estimator algorithm. In order to test the performance of the proposed control technique, a numerical model of the engine has been developed, which employs a thermodynamic (zero-dimensional) approach. The paper will show that the OSA technique is able to improve dramatically the control performance with respect to that provided by a commonly applied proportional integral derivative control technique.     

Optimal scheduling techniques for cluster tools with process-module and transport-module residency constraints

This paper discusses two scheduling techniques for dual-arm cluster tools that address both process-module and transport-module residency constraints and throughput requirements. The first technique is the extension of our previous work that only addressed process-module residency constraints. For cases with long process times, this technique can take a long time to find the solution and is not practical. Hence, we use this algorithm mainly as a benchmark for comparison. The second technique that uses a linear programming technique with use of several heuristics can find the optimal solution very efficiently. Analytical and experimental analysis of this technique shows the correctness, completeness and efficiency of this technique.     

Utilizing a novel root companding transform technique to reduce PAPR in OFDM systems

One major defect in orthogonal frequency division multiplexing systems is the high peak‐to‐average power ratio (PAPR) at the transmitter. The linear nonsymmetrical transform (LNST) technique, one of the companding transform (CT) techniques for PAPR reduction, offers excellent performance, but requires additional side information. In this paper, a new ‘root CT’ technique without additional side information is proposed, and it can reach a good trade‐off between the PAPR reduction and the bit error rate (BER). The theoretical analysis of the proposed root technique is also derived. The simulation results show that the proposed root CT technique can achieve more efficient PAPR reduction and better power spectrum density than those of the LNST technique. The BER of the proposed CT technique without additional side information is close to that of the LNST technique with additional side information when the AWGN or multipath fading channels are considered. Furthermore, the simulation results also demonstrate that the proposed technique offers better performance than that of the µ‐law technique over the AWGN and multipath fading channels. Copyright © 2010 John Wiley & Sons, Ltd.     

A power efficient gain enhancing technique for current mirror operational transconductance amplifiers

In this paper, a power efficient voltage gain enhancing technique is described. This technique is suitable for the amplifiers which use current starving method for gain enhancement (explained in the text). The proposed technique makes use of the current which conventionally goes to ground, through a parallel path. In this paper, the new technique is demonstrated for current mirror type of operational transconductance amplifier (OTA). Simulation results show that gain improves by a factor ~2, while consuming the same power as conventional OTA. The added advantage of this technique is that it does not affect the voltage swing while increasing the gain. Compared to the conventional current starving technique, the proposed technique also improves the noise performance and settling speed of the amplifier. The results are compared with the conventional technique, in terms of gain, settling and noise performance. A comparison of FoM (MHz.pF/mA), with other amplifiers, is given at the end as well.     

正交法窄带噪声调制技术

通过对窄带随机信号的理论分析,利用窄带随机信号的经典表达式,提出正交法窄带噪声调制技术。采用该技术使调制后的窄带噪声谱质量在最大程度上逼近直放式窄带白噪声。经过试验证明,该技术是一种最佳的窄带噪声调制技术,并且可以方便地实现工程化。     

Web动态查询技术

Web技术是一项很新的技术，它不仅为Internet的广泛普及起到关键性的作用，而且还在Intranet、电子商务等其他相关计算机网络应用技术发展中起到关键作用，目前它已成为计算机网络应用的一个主要技术，尤其重要的技术是Web动态技术。     

The equivalence of best plane fit gradient with Robert's,Prewitt's and Sobel's gradient for edge detection and a 4-neighbour gradient with useful properties

The best plane fit gradient edge detection technique is reexamined. It is shown that this technique for some different mask sizes and different point operator is equivalent to Robert's, Prewitt's, Sobel's and Huckel's gradient techniques. A 4-neighbour edge detection technique is defined and it is shown that this technique satisfies many desirable properties of an edge detector.     

应用基于抽象机的动态翻译设计Java处理器

本文提出了一种基于硬件抽象机的动态翻译技术,它可用于实现Java处理器.该技术采用了硬件抽象机的"模糊执行"(HAM)方法,通过分析Java程序之间的相关性,动态地将Java字节码转换成基于标签的类RISC指令.然后,将堆栈折叠与动态翻译相结合进一步优化指令.应用该技术设计了一个Java指令级并行处理器,并且扩展它,支持Java多线程功能.     

Modeling of thin dielectric structures using the finite-differencetime-domain technique

The finite-difference time-domain (FDTD) technique is applied to scattering problems involving thin dielectric sheets, conductor-backed dielectric sheets, and conductor-backed dielectric sheets containing cracks in the dielectric material. A smart cell technique is developed that enables these geometries to be modeled with a spatial grid that is much larger than the dielectric slab and crack widths. This technique is computationally more efficient than the `brute force' (or ordinary) FDTD approach, which must use cells small enough to resolve the dielectric sheets. Numerical results are presented which show that this technique yields accurate scattering results at a large savings in computational resources     

A novel ensembled technique for anomaly detection

Anomaly detection is a technique that works to detect those instances of data that do not comply with the data model. In this paper the problem of anomaly detection in networked traffic data is considered, and a novel ensembled technique for anomaly detection is proposed. The proposed technique uses a combination of fuzzy K‐means clustering algorithm, extended Kalman filter, and support vector machines to detect the anomalies. In the proposed technique, fuzzy membership functions are used instead of crisp clusters to compute the best set of features by fuzzy k‐means algorithm. These features are then optimized with a nonlinear Bayesian approach known as extended Kalman filter. The resultant optimized set of features is then provided as an input to the support vector machine classifier that detects the network anomalies. The proposed technique is validated by using 2 benchmark datasets, ie, DARPA 1998 and KDD CUP 1999. Experimental results indicate that the proposed technique performs quite well as compared to its traditional counterparts in accuracy, detection rate, false positive rate, and F‐score.     

浅论显示技术发展格局

显示技术领域的发展格局正在发生着巨大的变化,平板显示技术的飞速发展使得显像管技术面临严峻挑战,显示技术如何发展是显示器件产业急需考虑的现实问题。     

Analytical Diagnosis and Tuning of Narrowband Multicoupled Resonator Filters

A novel analytical filter diagnosis technique based on the partial fraction expansions of admittance matrix is proposed in this paper. The technique is applicable to computer-aided filter tuning of a general Chebyshev filter. The key issue in the proposed technique is the extension of the realizability conditions to the asynchronously tuned filters for removing the phase-loading effect. Using this analytical diagnosis technique, the inherent dispersion effects of the resonators and coupling elements are compensated by removable stray couplings in the diagnosed filter models. The filter topology that can be handled by this technique is only limited by the availability of the exact filter synthesis technique with which the filter to be diagnosed is designed.     

Determination of thermal resistance using Gummel measurement for InGaP/GaAs HBTs

In this paper, we propose a technique to determine thermal resistance of InGaP/GaAs heterojunction bipolar transistors (HBTs). The technique is based on Gummel measurement at only a few substrate temperatures. The major advantage of this technique is the simplicity in measurement, since the temperature-dependent parameter does not need to be determined for each device size. Therefore, when a number of devices need to be measured, this technique is less time-consuming. Another feature of this technique is the separation of the thermal resistance and emitter resistance, so that it is easier to optimize the emitter resistance. The result shown in this paper is measured from an InGaP/GaAs HBT, and is compared with another typical technique.     

新型电子工业清洗工艺研究

本文报告了一种新型电子工业清洗工艺。用该工艺清洗过的硅片上的钠残留量低于常规ｃｍｏｓ／ｓｏｓ栅氧化工艺，去重金属离子的能力及对器件参数的影响与常规ｃｍｏｓ／ｓｏｓ栅氧化工艺相当。新型清洗工艺具有操作简单，价格低廉等优点，无毒，无腐蚀性，对人体无危害，对环境无污染。