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1引言随着高通量生物技术的发展,生物学的实验手段和研究方法均发生了巨大的变革,由此带来的领域内实验数据的“指数性”增长,数据的存储与传输,数据的处理、理解与应用等一系列问题,得到了来自数学,化学,药学,统计学,计算机科学等领域专家的广泛关注并取得了大量成果。生物学文献作为成果展示和学术交流的主要方式之一,其数目之大,增长速度之快远远超过了其他学科领域。隶属于美国国家生物技术信息中心的文献摘要库MEDLINE,是世界上最大的、最具权威性的著名生物医学文献数据库,收集了全世界4800多种生物学及医学杂志上1500万余篇文献信… 相似文献
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Today's news readers can be easily overwhelmed by the numerous news articles online. To cope with information overload, online news media publishes timelines for continuously developing news topics. However, the timeline summary does not show the relationship of storylines, and is not intuitive for readers to comprehend the development of a complex news topic. In this paper, we study a novel problem of exploring the interactions of storylines in a news topic. An interaction of two storylines is signified by informative news events that play a key role in both storylines. Storyline interactions can indicate key phases of a news topic, and reveal the latent connections among various aspects of the story. We address the coherence between news articles which is not considered in traditional similarity-based methods, and discover salient storyline interactions to form a clear, global picture of the news topic. User preference can be naturally integrated into our method to generate query-specific results. Comprehensive experiments on ten news topics show the effectiveness of our method over alternative approaches. 相似文献
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基于RBF核的SVM的模型选择及其应用 总被引:22,自引:2,他引:22
使用RBF核的SVM(支持向量机)被广泛应用于模式识别中。此类SVM的模型选择取决于两个参数,其一是惩罚因子C,其二是核参数σ2。该文使用了网格搜索和双线性搜索两种方法进行参数选择,并将两者的优点综合,应用于脱机手写体英文字符识别。实验在NIST数据集上进行了验证,对搜索效率和推广识别率进行了比较。实验结果还表明使用最优参数的SVM在识别率上比使用ANN(人工神经元网络)的分类器有较大提高。 相似文献
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A new speaker verification method with global speaker model and likelihood score normalization 下载免费PDF全文
In this paper a new text-independent speaker verification method GSMSV is proposed based on likelihood score normalization.In this novel method a global speaker model is established to represent the universal features of speech and normalize the likelihood score.Statistical analysis demonstrates that this normalization method can remove common factors of speech and bring the differences between speakers into prominence.As a result the equal error rate is decreased significantly,verification procedure is accelerated and system adaptability to speaking speed is improved. 相似文献
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研究不同复合包埋材料对含腈水解酶的Gibberella intermedia CA3-1进行固定化,选择出最为适合的壳聚糖-聚乙烯醇作为复合包埋材料,其优化后的浓度分别为1.6%和2%。实验结果表明该固定化细胞的最适转化条件为:3-氰基吡啶初始浓度300mmol/L,转化温度30℃,pH值7.0,转化时间60min。固定化细胞可以稳定进行26个批次转化,每克干细胞可转化产生283.5g烟酸,为游离细胞的3倍。此外,固定化细胞对高浓度3-氰基吡啶的耐受性大幅提高,温度稳定性有一定增强。连续补料19次,固定化细胞酶活保留约30%,经折算产率为每克干细胞转化生成191.3g烟酸。 相似文献
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以单片机(AT89S51)为控制核心,用温度传感器对温度进行实时采集,利用时钟芯片构成万年历,最后通过液晶显示屏把各项参数显示出来。外部设备的启停由温度的整定值来控制。时钟芯片可以准确显示年、月、日、时、分、秒,还可以设置闹铃。通过键盘可以方便的实现画面切换、各项参数的设置、唤醒等操作。 相似文献