蓝牙资格认证解析

蓝牙资格认证要求所有使用蓝牙标准的设计和产品都要符合测试标准。介绍了蓝牙的认证流程,包括产品概念、测试计划、产品测试和产品列表;并且针对于不同的产品,从测试、文档、评估、声明、列表、标识、符合稽查和强制要求方面介绍了应满足的蓝牙认证要求。     

Crystallization of vitamin C in a continuous DT MSMPR crystallizer – Size independent growth kinetic model approach

The experimental results concerning continuous mass crystallization process in L(+)‐ascorbic acid – water system are presented and discussed. Influence of L(+)‐ascorbic acid concentration in a feeding solution and mean residence time of suspension in laboratory DT MSMPR crystallizer on product crystal size distribution as well as nucleation and growth kinetics were determined. Kinetic parameter values were evaluated on the basis of size–independent growth (SIG) kinetic model (McCabe's ΔL law). It was observed, that within the examined range of crystallizer productivity (120–1600 kg LAA crystals m^–3h^–1) crystal product population of mean size L_m from 0.2 to 0.3 mm and CV from 66.6 to 49% is withdrawn. Linear growth rate values present decreasing trend (from ca. 7 · 10^–8 to ca. 6 · 10^–8 m s^–1) with the productivity increase (assuming constant mean residence time of suspension τ = 900 s). Occurrence of secondary nucleation within the circulated and mixed suspension, resulting from crystal attrition and breakage, was observed. The parameter values in design equation connecting linear growth rate and suspension density with nucleation rate were determined. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Stable adaptive channel estimation method under impulsive noise environments

Channel estimation is one of the key technologies for ensuring reliable wireless communications under impulsive noise environments. This paper studies robust adaptive channel estimation methods for mitigating harmful impulsive noises, which are described as alpha‐stable (α ‐stable) distribution models. Traditional adaptive channel estimation using the second‐order statistics based least mean square (SOS‐LMS) algorithm does not perform well under α ‐stable noise environments, even though it was considered one of attractive approaches for estimating channels in the case of Gaussian noises. Unlike the traditional SOS‐LMS algorithm, in this research, we propose a stable sign‐function‐based LMS algorithm, which can mitigate the impulsive noises. Specifically, we first construct the cost function with minimum ℓ ₁‐norm error criterion and then derive the updating equation of the proposed algorithm. Compared with the traditional SOS‐LMS, the effectiveness of the proposed algorithm is validated via Monte Carlo simulations in various α ‐stable noise scenarios. Copyright © 2015 John Wiley & Sons, Ltd.     

蓝牙技术与其产品认证

蓝牙(Bluetooth)技术作为一项无线个人局域网络的开放标准，正越来越多地受到生产厂商和研究机构的广泛关注。本文简单介绍了蓝牙技术及其标准化状况。对蓝牙特别兴趣集团(SIG)所组织,开展的产品认证要求和认证程序进行了描述。     

Feature extraction and recognition for echoes of HRR radar

This paper describes a novel target recognition scheme using High Range Resolution (HRR) ra-dar signatures. AutoRegressive (AR) method is used to extract features from HRR radar echoes based on scattering center model of target. The optimal linear transformation based on Euclidian distribution distance criterion is performed on AR model parameter vectors to reduce dimension of feature vectors further and improve the class discrimination capability of feature vectors. The optimization algorithm is designed utiliz-ing the quadratic property of criterion function and Gaussian kernel based Parzen window density function estimator. The concept of Stochastic Information Gradient (SIG) is incorporated into the gradient of cost function to decrease the computational complexity of the algorithm. Simulation results using three real air-planes, data show the effectiveness of the proposed method.     

蓝牙认证V5.2和V5.1版解析

介绍了蓝牙认证中V5.2、V5.1版本在功能、协议层及射频一致性等方面的主要差异及认证流程、测试流程、注意事项等,企业可根据自己的产品选择合适的蓝牙认证标准。     

基于WSRF框架的空间信息服务技术

针对当前基于Web服务的空间信息格网(Spatial Information Grid, SIG)系统无法获取资源中间状态的缺点,探讨了一种基于Web服务资源框架(Web Service Resource Framework, WSRF)构建SIG的实现技术,而使SIG成为一种能够提供资源中间状态(stateful)的系统,有利于客户端与服务端的持久交互和状态回溯.在介绍了WSRF框架及其实现方式的基础上,探讨了基于WSRF构建空间信息服务的流程和关键,即确定系统中状态化的资源种类和空间信息服务.以地理坐标转换为例示范了状态化服务资源的创建过程,并提出了基于WSRF的SIG服务框架.     

偏代数族的积偏代数

定义了一族偏代数物积偏代数的概念，且对偏代数间的同态映射，由同态映射诱导的合同关系及由同态映射和合同关系诱导的合同关系与积偏代数一起作了深入的讨论，分别得到了一些有意义的结果。