VLSI architectural design tradeoffs for sliding-window log-MAP decoders

Turbo codes have received tremendous attention and have commenced their practical applications due to their excellent error-correcting capability. Investigation of efficient iterative decoder realizations is of particular interest because the underlying soft-input soft-output decoding algorithms usually lead to highly complicated implementation. This paper describes the architectural design and analysis of sliding-window (SW) Log-MAP decoders in terms of a set of predetermined parameters. The derived mathematical representations can be applied to construct a variety of VLSI architectures for different applications. Based on our development, a SW-Log-MAP decoder complying with the specification of third-generation mobile radio systems is realized to demonstrate the performance tradeoffs among latency, average decoding rate, area/computation complexity, and memory power consumption. This paper thus provides useful and general information on practical implementation of SW-Log-MAP decoders.     

Ferromagnetism and the Optical Properties of Mn-Doped CdSe with the Wurtzite Structure

The geometrical structure of CdSe was optimized by using the ultrasoft pseudopotential method of a total energy plane wave based on density functional theory. The band structure, density of states, and optical properties were calculated and discussed in detail. The Mn-doped CdSe is found to be a half-metallic ferromagnet with 100% carrier spin polarization at the Fermi level. At a Mn concentration of 12.5%, the calculated total energy of the spin-polarized state is 614 meV lower than that of the nonspin-polarized state. The net magnetic moment of 5 μ _B is found per supercell for 12.5% Mn-doped CdSe. The estimated Curie temperature of 748.6 K for Mn-doped CdSe is above room temperature. The ferromagnetic ground state in Mn-doped CdSe can be explained in terms of the p ? d hybridization mechanism. These results suggest that Mn-doped CdSe may present a promising dilute magnetic semiconductor, and may have potential applications in the field of spintronics.     

基于概念格的规则产生集挖掘算法

传统的规则提取算法产生的规则集合相当庞大，其中包含许多冗余的规则．使用闭项集可以减少规则的数目，而概念格结点问的泛化和例化关系非常适用于规则提取．基于概念格理论和闭项集的概念，提出了一种新的更有利于规则提取的格结构，给出了相应的基于闭标记的渐进式构造算法和规则提取算法．最后提供给用户的是直观的、易理解的规则子集，用户可以有选择地从中推导出其他的规则．实验表明该方法能够高效地挖掘规则产生集．     

Cloud Based Software Computing as a Service in Hybrid Evolution Algorithm with Feedback Assistance

This paper develops cloud based software computing as a service (SCaaS) in the hybrid evolution algorithm with feedback assistance to solve the data optimal NP-complete problems such as travel salesman problems and job shop scheduling problems. Suitable steps, methods, or procedures of the genetic algorithm can be adopted from various evolution procedures or methods of the genetic algorithms based on the fitness evaluation results and survival ratio of different crossover methods in the current generation. The proposed system can dynamically emphasize the corresponding methods or procedures for the better performance in optimal solution searching. In addition, according to the proposed XML format, system users can upload only the coding of chromosomes without implementing the genetic algorithm program. Furthermore, by using the feedback assistance, the convergence time of the optimal solution can be enhanced.     

Review on multi-criteria decision analysis aid in sustainable energy decision-making

Multi-criteria decision analysis (MCDA) methods have become increasingly popular in decision-making for sustainable energy because of the multi-dimensionality of the sustainability goal and the complexity of socio-economic and biophysical systems. This article reviewed the corresponding methods in different stages of multi-criteria decision-making for sustainable energy, i.e., criteria selection, criteria weighting, evaluation, and final aggregation. The criteria of energy supply systems are summarized from technical, economic, environmental and social aspects. The weighting methods of criteria are classified into three categories: subjective weighting, objective weighting and combination weighting methods. Several methods based on weighted sum, priority setting, outranking, fuzzy set methodology and their combinations are employed for energy decision-making. It is observed that the investment cost locates the first place in all evaluation criteria and CO₂ emission follows closely because of more focuses on environment protection, equal criteria weights are still the most popular weighting method, analytical hierarchy process is the most popular comprehensive MCDA method, and the aggregation methods are helpful to get the rational result in sustainable energy decision-making.     

连续结构微带滤波器的矩阵运算法分析

用矩阵运算法对“均匀”和“等比”两种连续结构的带阻及低通滤波器进行了研究,分析了结构参数对滤波器性能的影响.实际制作并测试了滤波器,理论与实验结果基本一致.     

The fracture behavior of multiple cracks emanating from a circular hole in piezoelectric materials

Using the complex variable method and a new conformal mapping, the fracture behavior of multiple cracks emanating from a circular hole in piezoelectric materials is considered under remotely uniform in-plane electric and anti-plane mechanical loadings. The analytic solutions of the field intensity factors and the energy release rate are presented by taking the effect of dielectric permittivity into consideration. Known results can be derived as special cases from the general solutions. The results are illustrated with plots, showing that the piezoelectric material containing three radial cracks spaced equally at 120° apart originating from a circular hole is the easiest to fail for all cases of cracks originating from a circular hole under in-plane electric and anti-plane mechanical loadings. Moreover, if there exist multiple cracks (n ≥ 3) originating from a circular hole in piezoelectric materials, an increase in the number of cracks can enhance the reliability of these materials. The star-shaped cracks possess similar characteristics.     

Refinement of Enhanced Speech Using Hybrid-Median Filter and Harmonic Regeneration Approach

This study proposes a post-processor to improve the harmonic structure of a vowel in an enhanced speech, enabling the speech quality to be improved. Initially, a speech enhancement algorithm is employed to reduce the background noise for a noisy speech. Hence the enhanced speech is post-processed by a hybrid-median filter to reduce the musical effect of residual noise. Since the harmonic spectra are impacted by background noise and a speech enhancement process, the quality of a vowel is deteriorated. A harmonic regenerated method is developed to improve the quality of post-processed speech. Experimental results show that the proposed method can improve the quality of post-processed speech by adequately regenerating harmonic spectra.     

β-Sialon-Nd-黄长石固溶体材料的生成和氧化行为

研究了在β10－Sialon（Si5．23Al0.77O0．77N7，23）中加入7．26Wt％Nd-黄长石固溶体（Nd2Si2AlO4N3）组份的反应过程和致密化行为．烧结过程中，稀土元素先进入α－Sialon；随温度的升高，稀土元素存在于晶界玻璃相中，并在退火过程中以黄长石相析出．对热压及经退火处理的样品，研究了其在1000～1400℃的氧化行为．1000℃氧化时，作为晶界相的黄长石固溶体并不会导致样品开裂．但在更高温度氧化时，氧化后的表面存在择优取向的A－Nd2Si2O7晶粒，且由于Nd离子的表面偏析使表面氧化层软化而形成气泡．     

电感耦合等离子质谱法检测保健食品中的硅

目的建立电感耦合等离子体质谱法检测保健食品中硅含量的分析方法。方法将保健食品类试样进行灰化,加入氢氧化钠形成共熔体,将共熔体与水混合,得到溶解液,采用电感耦合等离子体质谱法对溶解液进行硅含量检测。通过加标回收率和国家标准物质的分析实验验证该方法的准确性和可靠性。结果实验标准曲线的线性范围在0.0～10.0μg/mL,回归方程的相关系数达到1.0000。方法的检出限为0.050 mg/L,标准物质加标回收率在96.4%～103.3%,精密度小于2.5%;国家标准物质柑橘叶和紫菜测定值均在标准值允许的范围内。结论该方法具有快速、批量、灵敏度高的特点,适用于保健食品中硅含量的测定。