一种用于SOC设计中的智能I/O处理器的实现

文章介绍了SOC设计流程，智能I／O处理器组成，在开发该处理器对VHDL源代码的优化问题。     

A dual-mode multiuser detector for DS-CDMA systems

We introduce a dual-mode multiuser detector that dynamically switches its detection mode between matched-filter and decorrelator operations based on the channel characteristics. This detector significantly reduces the overall computational requirement while maintaining similar performance as that of the decorrelator. The switching mechanism of our dual-mode detector is designed by exploiting the performance-complexity tradeoff between the decorrelator and the matched-filter. Extensions of this idea to other types of multiuser detectors are also proposed     

关于化粪池几个问题的探讨

探讨化粪池在设计布置及使用管理中应注意的几个问题，以充分发挥化粪池在保护环境，减轻污染方面的作用。     

A novel method for elimination of line-current harmonics insingle-stage PFC switching regulators

This paper studies a particular single-stage power-factor-correction (PFC) switching regulator employing a discontinuous-conduction-mode (DCM) boost-input cell and a continuous-current-mode (CCM) forward output cell. Although this single-stage PFC regulator can provide a reasonably high power factor when its PFC stage is operating in discontinuous mode, substantial reduction in line-current harmonics is possible by applying a suitable frequency-modulation scheme. This paper derives a frequency-modulation scheme and proposes a practical implementation using a simple translinear analog circuit. A quantitative analysis on the total harmonic distortion (THD) of the line current when the circuit is subject to a limited range of frequency variations is presented along with some considerations for practical design. Experimental data obtained from a prototype confirms the effectiveness of the proposed frequency-modulation scheme. The proposed analog translinear circuit allows custom integrated circuit implementation, making it a viable low-cost solution to the elimination of line-current harmonics in switching regulators     

Representing context, cognition, and crew performance in a shutdown risk assessment

This paper presents a potentially practical treatment of dynamic operator-system interactions. The approach employs a dynamic event tree framework to explicitly address plant dynamics, system indications, crew-plant interactions, time available, crew cognition, errors of commission (mistakes), and multiple planning and diagnosis possibilities. The approach is applied in an analysis of a hypothesize medium break loss of coolant accident for a test reactor that occurs during plant shutdown. This transient was selected on the basis of: a significant cognitive component being present, high consequences being associated with operator actions, and the importance of event timing to scenario progression. The results presented show how quantitative risk predictions are affected by the treatment of dynamics, and demonstrate how non-proceduralized recovery actions and a number of performance shaping factors (e.g., crew experience, stress, and confidence) can be explicitly treated. Insights and lessons learned regarding the performance of a dynamic assessment are also presented.     

Optical properties of Nd-doped Ca3(VO4)2 single crystal fiber

Optical absorption and photoluminescence of Ca₃(VO₄)₂ single crystal grown by a floating-zone technique and containing Nd³⁺ ions were investigated. High absorption coefficients and broadening of most absorption bands are present at 300 K, while substructures in some of the same bands can be evidenced at 12 K. Most features of measured spectra are characteristic of random occupation of more than a single Ca²⁺ site by the Nd³⁺ ion and of distortions provoked by different charge compensation mechanisms involving oxygen vacancies promotion in the crystal lattice. Nd³⁺ optical properties were studied by using the Judd-Ofelt theory to calculate the spectral parameters relevant for laser applications.     

A systematic design method to obtain broadband characteristics for singly-fed electromagnetically coupled patch antennas for circular polarization

We present a systematic, empirical design technique to obtain optimum broadband impedance, axial-ratio (AR) and gain bandwidths for a singly-fed electromagnetically coupled patch antenna for circular polarization. Our investigation has also revealed tradeoffs amongst obtainable AR, impedance bandwidth and AR bandwidth. Using two design examples at different frequency bands and for different senses of circular polarization, we have demonstrated the effectiveness of the proposed knowledge-based tuning method. We have obtained at C-band measured values of impedance bandwidth (VSWR/spl les/2) equal to 43%, 3-dB AR bandwidth of 8%, AR of less than 0.3 dB and a mean gain level of 7 dB. For the Ku-band element, a 40% impedance bandwidth and a 17.3% of 3-dB AR bandwidth have been obtained with a peak gain of 7.2 dBic.     

A technique for extracting physiological parameters and therequired input function simultaneously from PET image measurements:theory and simulation study

Positron emission tomography (PET) is an important tool for enabling quantification of human brain function. However, quantitative studies using tracer kinetic modeling require the measurement of the tracer time-activity curve in plasma (PTAC) as the model input function. It is widely believed that the insertion of arterial lines and the subsequent collection and processing of the biomedical signal sampled from the arterial blood are not compatible with the practice of clinical PET, as it is invasive and exposes personnel to the risks associated with the handling of patient blood and radiation dose. Therefore, it is of interest to develop practical noninvasive measurement techniques for tracer kinetic modeling with PET. In this paper, a technique is proposed to extract the input function together with the physiological parameters from the brain dynamic images alone. The identifiability of this method is tested rigorously by using Monte Carlo simulation. The results show that the proposed method is able to quantify all the required parameters by using the information obtained from two or more regions of interest (ROIs) with very different dynamics in the PET dynamic images. There is no significant improvement in parameter estimation for the local cerebral metabolic rate of glucose (LCMRGlc) if there are more than three ROIs. The proposed method can provide very reliable estimation of LCMRGlc, which is our primary interest in this study     

无约束淬火机目标温度神经网络预报

淬火、控制冷却的冷却速度和目标温度是关系到钢板性能的关键因素 ,但由于冷却过程的水量、水温、辊道速度等对冷却目标温度的影响属多变量非线性过程 ,用简单的解析模型通常精度较低 ,难以达到精确控制的要求。采用人工神经网络技术对无约束淬火机目标温度进行快速预报 ,结果表明 ,预测精度高 ,快速准确     

Articulatory-feature-based confidence measures

Confidence measures are computed to estimate the certainty that target acoustic units are spoken in specific speech segments. They are applied in tasks such as keyword verification or utterance verification. Because many of the confidence measures use the same set of models and features as in recognition, the resulting scores may not provide an independent measure of reliability. In this paper, we propose two articulatory feature (AF) based phoneme confidence measures that estimate the acoustic reliability based on the match in AF properties. While acoustic-based features, such as Mel-frequency cepstral coefficients (MFCC), are widely used in speech processing, some recent works have focus on linguistically based features, such as the articulatory features that relate directly to the human articulatory process which may better capture speech characteristics. The articulatory features can either replace or complement the acoustic-based features in speech processing. The proposed AF-based measures in this paper were evaluated, in comparison and in combination, with the HMM-based scores on phoneme and keyword verification tasks using children’s speech collected for a computer-based English pronunciation learning project. To fully evaluate their usefulness, the proposed measures and combinations were evaluated on both native and non-native data; and under field test conditions that mis-matches with the training condition. The experimental results show that under the different environments, combinations of the AF scores with the HMM-based scores outperforms HMM-based scores alone on phoneme and keyword verification.