Case-based context ontology construction using fuzzy set theory for personalized service in a smart home environment

To provide context-based personalized services utilizing smart appliances in a smart home environment, we propose a framework for PersonAlized Service disCovery Using FuZZY-based CBR and Context Ontology (PASCUZZY). Basically, the PASCUZZY framework is implemented on case-based context ontology. To generate and manage the case instances on the case-based context ontology, we adopt the fuzzy set theory to transpose numerical-type context data sensed from the surrounding environment. The context is transposed to linguistic-type context instances on the context ontology. In addition, to formalize and manage the context and services as multi-attributed data, the context ontology was developed reflecting the structure of cases borrowed from case-based reasoning. Furthermore, we propose adaptation methods to adjust the generic fuzzy membership functions depending on the inhabitants’ context. It is performed by modifying the values of the membership number and/or modifying the numbers of the linguistic terms that are based on the inhabitants’ context to affect the membership numbers. The adapted membership functions return the personalized degree of memberships depending on the specialized context of a specific fuzzy variable. Inevitably, the number of cases on the case-based context ontology will be increased from time to time. We apply Ward’s method not only to reduce the search effort via a hierarchical clustering on the case-based context ontology but also to find the most similar service as a solution to the new context. To verify the superiority of the PASCUZZY framework, we perform two kinds of evaluations. First, we evaluate the effectiveness of the adaptation of the fuzzy membership functions. Second, we verify the effectiveness of the application of a clustering method to the case instances of the case-based context ontology to identify the most similar service. Results of the experiment verified the effectiveness and superiority of the PASCUZZY framework.     

A hardware-based algorithm for virtual machine provisioning in a private cloud

Cloud computing is becoming a key factor in the market day by day. Therefore, many companies are investing or going to invest in this sector for development of large data centers. These data centers not only consume more energy but also produce greenhouse gases. Because of large amount of power consumption, data center providers go for different types of power generator to increase the profit margin which indirectly affects the environment. Several studies are carried out to reduce the power consumption of a data center. One of the techniques to reduce power consumption is virtualization. After several studies, it is stated that hardware plays a very important role. As the load increases, the power consumption of the CPU is also increased. Therefore, by extending the study of virtualization to reduce the power consumption, a hardware-based algorithm for virtual machine provisioning in a private cloud can significantly improve the performance by considering hardware as one of the important factors.     

PalmPhasor算法性能的理论分析

模板的安全性和隐私性是掌纹系统实际应用的关键问题,然而生物特征保护的多项指标通常相互冲突并且难以同时满足.作为解决上述冲突的一种可撤销掌纹编码算法,PalmPhasor实现了高效、安全的掌纹认证.建立了系统分析PalmPhasor性能的完整框架.为了便于具体分析,将情景分为4种情况,并且提供了支持相应分析的预备知识,包括辅助定理以及Gabor滤波掌纹图像实部和虚部分布特性.在统计学基础上建立的理论分析和实验结果均表明:即使在用户口令被盗的情况下,多方向分数级融合增强的PalmPhasor算法也可以同时有效地满足可撤销生物特征的4项指标.     

公交车辆用可燃气体检测仪

以可编程门阵列器件FPGA和气体传感器MQ-3为核心,设计了能检测可燃物挥发气的车载式检测仪.为了保证灵敏度,采用了差动集气管结构;为了免人工维护,采用了气泵正、反转集气、吹扫双功能;所有部件小巧,适合安装在车门附近的狭小空间内.最后对差动集气管效果、敏感探测距离进行了实验.     

A weight function-critical plane approach for low-cycle fatigue under variable amplitude multiaxial loading

Low‐cycle fatigue data of type 304 stainless steel obtained under axial‐torsional loading of variable amplitudes are analyzed using four multiaxial fatigue parameters: SWT, KBM, FS and LKN. Rainflow cycle counting and Morrow's plastic work interaction rule are used to calculate fatigue damage. The performance of a fatigue model is dependent on the fatigue parameter, the critical plane and the damage accumulation rule employed in the model. The conservatism and non‐conservatism of predicted lives are examined for some combinations of these variables. A new critical plane called the weight function‐critical plane is introduced for variable amplitude loading. This approach is found to improve the KBM‐based life predictions.     

Preparation of patterned SiC and SiCN microstructures

With the development of modern science and technology, the importance of small structures or microstructures (such as the fluidic nanostructure or microreactor[1], the in- tegrate circuit in microelectronics[2], the factory in a chip[3,4], etc.) has been incarnated day by day in the fields of microelectronics, micro-optical systems, microanalytical sys- tems, microelectromechanical systems and cytobiology. And the fabrication technique (microfabrication) of the small structures has become the h…     

大型汽轮发电机主绝缘耐压和电老化试验中定子线棒端部防晕技术的研究

大型汽轮发电机在主绝缘耐压和电老化试验中,可能出现定子线棒端部闪络和防晕层过热的情况,从而损伤主绝缘,影响试验顺利进行。本文通过建立真机线棒端部的Pspice仿真模型,模拟了线棒端部绝缘表面电场分布,分析了端部闪络的原因。通过进一步的仿真研究,提出了线棒端部防晕的技术方案,并试制了线棒端部防晕装置。试验结果表明,该防晕装置可有效防止线棒端部闪络和防晕层过热。     

Variable step-size affine projection algorithm based on global speech absence probability for adaptive feedbackcancellation简

A novel approach is proposed for improving adaptive feedback cancellation using a variable step-size affine projection algorithm（VSS-APA） based on global speech absence probability（GSAP）.The variable step-size of the proposed VSS-APA is adjusted according to the GSAP of the current frame.The weight vector of the adaptive filter is updated by the probability of the speech absence.The performance measure of acoustic feedback cancellation is evaluated using normalized misalignment.Experimental results demonstrate that the proposed approach has better performance than the normalized least mean square（NLMS） and the constant step-size affine projection algorithms.     

孤岛运行方式下微电网储能系统能量成型控制策略

在分析微电网储能系统(ESS)结构的基础上,建立了微电网ESS的端口受控哈密顿(PCH)模型,设计了PCH控制器,确定了期望平衡点,给出了微电网ESS的能量成型控制策略。建立含可再生能源发电单元和ESS的微电网仿真模型对所提策略进行仿真,仿真结果表明,与典型PI闭环线性控制策略相比,所提控制策略在孤岛运行期间能很好地满足对ESS的控制要求,且具有更好的快速性、鲁棒性。