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991.
明亮  陈大庆 《现代雷达》2018,40(6):54-56
提出一种高效的工作频率评估技术,通过双向自动映射,在规划和探测过程中对雷达波位的工作频率进行预先或实时评估,帮助用户提供操作参考。通过对工作频率评估技术的应用验证,该技术能自动及时提供工作频率评估结果,提高了人机交互效率,促进了雷达探测性能的提升。  相似文献   
992.
An implantable optrode composed of fiber and multi-channel flexible thin-film electrode is developed. The flexible recording electrode is made from polyimide and is wrapped around the optical fiber. The front end of the fiber is tapered by wet etching. With the tapered shape, the light can leak from the sidewall of the fiber, and the tapered tip makes it easy to be implanted. The flexible electrode is attached with its recording sites aligning to the tapered part on the fiber. With this method, the fiber acts as an optical waveguide, as well as a support probe for flexible thin-film electrode. This novel device simplifies the fabrication process and decreases the size of the optrode. The device works well in vivo and the optical caused spike can be recorded with signal-to-noise ratio of 6:1.  相似文献   
993.
廖欣  郑欣  邹娟  冯敏  孙亮  杨帆 《液晶与显示》2018,33(4):347-356
针对宫颈细胞病理图像自动筛查问题,本文提出一种基于人工智能技术的计算机辅助诊断方法。该方法通过对宫颈细胞病理图像采用自适应双阈值法进行初步检测,再采用改进Chan-Vase模型进行精确分割,提取出细胞(粘连簇团)中的不同区域。然后,结合病理诊断专家规则,构建相应的正交特征集。在此基础上,使用神经网络集成模型进行正常、疑似病变二分类识别,完成计算机辅助诊断。实验表明,本文方法能够有效完成宫颈病理细胞(粘连簇团)的分类识别,具有较高的正确率(84%)与较低的误判率(2.1%)。满足了在保证判断正确率的条件下,尽量降低将疑似病变样本误判为正常样本的实际病理诊断要求。  相似文献   
994.
赵岩  周真  王东辉 《光电子快报》2019,15(5):396-400
An abundance estimation algorithm based on orthogonal bases is proposed to address the problem of high computational complexity faced by most abundance estimation algorithms that are based on a linear spectral mixing model (LSMM) and need to perform determinant operations and matrix inversion operations. The proposed algorithm uses the Gram-Schmidt method to calculate the endmember vector set to obtain the corresponding orthogonal basis set and solve the unmixing equations to obtain the eigenvector of each endmember. The spectral vector to be decomposed is projected onto the eigenvector to obtain projection vector, and the ratio between the length of the projection vector and the length of the orthogonal basis corresponding endmember is calculated to obtain an abundance estimation of the endmember. After a comparative analysis of different algorithms, it is concluded that the proposed algorithm only needs to perform vector inner product operations, thereby significantly reducing the computational complexity. The effectiveness of the algorithm was verified by experiments using simulation data and actual image data.  相似文献   
995.
Traditional wireless communications only utilize fixed-rate multicast and broadcast. In other words, only the most robust modulation and coding scheme can be applied for data transmission. Such a scheme fails to sufficiently exploit the potential gains of multicast and broadcast, resulting in bandwidth waste. To overcome such a problem, investigating the rate adaptation of multicast and broadcast wireless systems is the primary task. Unlike the traditional wireless systems, this paper presents an analytical model with rate adaptation for both multicast and broadcast. Adaptive modulation and coding are applied to achieve rate adaptation. We construct a stochastic model by using Finite State Markov chains for the multicast broadcast system modeling. The model’s outputs are shown to approximate to the results of our system level simulations. The model derives the performance of rate adaptation in multicast and broadcast. With the deduced modeling results, we can predict the system throughput providing the channel states, and the modulation and coding schemes variations.  相似文献   
996.
Clustering analysis is a promising data-driven method for analyzing functional magnetic resonance imaging (fMRI) time series data. The huge computational load, however, creates practical difficulties for this technique. We present a novel approach, integrating principal component analysis (PCA) and supervised affinity propagation clustering (SAPC). In this method, fMRI data are initially processed by PCA to obtain a preliminary image of brain activation. SAPC is then used to detect different brain functional activation patterns. We used a supervised Silhouette index to optimize clustering quality and automatically search for the optimal parameter p in SAPC, so that the basic affinity propagation clustering is improved by applying SAPC. Four simulation studies and tests with three in vivo fMRI datasets containing data from both block-design and event-related experiments revealed that functional brain activation was effectively detected and different response patterns were distinguished using our integrated method. In addition, the improved SAPC method was superior to the k -centers clustering and hierarchical clustering methods in both block-design and event-related fMRI data, as measured by the average squared error. These results suggest that our proposed novel integrated approach will be useful for detecting brain functional activation in both block-design and event-related experimental fMRI data.  相似文献   
997.
刘杰  赵洪  王鹏  蒋亮  黄超 《光电子.激光》2011,(12):1789-1792
针对交流电流的测量,提出了一种基于分布式反馈(DFH)激光器解调技术的光学电流互感器(0CT)。OCT的传感部分运用光纤Bragg光栅(FBG)和超磁致伸缩材料(GIⅢ①作为传感器探头,同时应用DFB激光器对FBG进行解凋,实现交流电流的测量。对于这种新型的OCT进行了理论分析和实验研究,实验测得系统传感灵敏度可达到1...  相似文献   
998.
This paper presents a novel energy-aware algorithm for service composition based on sharing routes in Wireless Sensor Networks (WSNs). The method integrates the resource of the overlapping WSNs to a virtual resource pool in the execution cycles of the workflow. This approach chooses the suitable service instances according to the current execution environment and user requirements with minimum energy consumption. Finally, the performance of sharing routes service composition selection in WSNs has been evalu...  相似文献   
999.
在简单分析传统价值链与虚拟价值链的基础上,总结出产业价值链结构的变化趋势,进而详细讨论我国电信产业价值链结构演进的3个阶段,并分析电信运营商在不同阶段的作用与定位.最后,针对未来电信产业价值链的变化趋势,为电信运营商的发展提出建议.  相似文献   
1000.
Device degradation behaviors of typical-sized n-type metal-induced laterally crystallized polycrystalline silicon thin-film transistors were investigated in detail under two kinds of dc bias stresses: hot-carrier (HC) stress and self-heating (SH) stress. Under HC stress, device degradation is the consequence of HC induced defect generation locally at the drain side. Under a unified model that postulates, the establishment of a potential barrier at the drain side due to carrier transport near trap states, device degradation behavior such as asymmetric on current recovery and threshold voltage degradation can be understood. Under SH stress, a general degradation in subthreshold characteristic was observed. Device degradation is the consequence of deep state generation along the entire channel. Device degradation behaviors were compared in low Vd-stress and in high Vd-stress condition. Defect generation distribution along the channel appears to be different in two cases. In both cases of SH degradation, asymmetric on current recovery was observed. This observation, when in low Vd-stress condition, is tentatively explained by dehydrogenation (hydrogenation) effect at the drain (source) side during stress  相似文献   
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