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声目标识别技术研究 总被引:2,自引:0,他引:2
吕永林 《楚雄师范学院学报》2008,23(3):24-31
本文对声目标识别的关键技术进行研究,探讨用小波分析来进行声信号处理和特征提取,用BP神经网络和支持向量机的模式分类方法来进行分类识别.通过对四种声信号的仿真实验表明,使用小波变换和人工神经网络技术及支持向量机分类技术相结合对声目标进行识别是有效、可行的. 相似文献
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文章从拉格朗日中值定理的几何意义出发,通过几何直观,利用向量运算构造适合罗尔中值定理条件的辅助函数,应用罗尔中值定理得到了拉格朗日中值定理的简捷证明。 相似文献
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Several tasks used in research studies are presented with assessment rubrics and examples of the development of student understanding. The tasks focus on students’ appreciation of variation in several contexts and illustrate the need to discuss variation in the classroom and to ask students specifically about it during assessment. 相似文献
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This article explores the social determinants of adolescents’ access to education during the COVID-19 pandemic in three diverse urban contexts in Bangladesh, Ethiopia and Jordan. It provides novel empirical data from the Gender and Adolescence: Global Evidence longitudinal study, drawing on phone surveys (4441), qualitative interviews with adolescents aged 12–19 years (500), and key informant interviews conducted between April and October 2020. Findings highlight that the pandemic is compounding pre-existing vulnerabilities to educational disadvantage, and that gender, poverty and disability are intersecting to deepen social inequalities. The paper concludes by reflecting on policy implications for inclusive distance education in emergencies. 相似文献
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Shubham Goel Ravinder Kumar Munish Kumar Vikram Chopra 《Information processing & management》2019,56(3):1053-1066
In the whole world, the internet is exercised by millions of people every day for information retrieval. Even for a small to smaller task like fixing a fan, to cook food or even to iron clothes persons opt to search the web. To fulfill the information needs of people, there are billions of web pages, each having a different degree of relevance to the topic of interest (TOI), scattered throughout the web but this huge size makes manual information retrieval impossible. The page ranking algorithm is an integral part of search engines as it arranges web pages associated with a queried TOI in order of their relevance level. It, therefore, plays an important role in regulating the search quality and user experience for information retrieval. PageRank, HITS, and SALSA are well-known page ranking algorithm based on link structure analysis of a seed set, but ranking given by them has not yet been efficient. In this paper, we propose a variant of SALSA to give sNorm(p) for the efficient ranking of web pages. Our approach relies on a p-Norm from Vector Norm family in a novel way for the ranking of web pages as Vector Norms can reduce the impact of low authority weight in hub weight calculation in an efficient way. Our study, then compares the rankings given by PageRank, HITS, SALSA, and sNorm(p) to the same pages in the same query. The effectiveness of the proposed approach over state of the art methods has been shown using performance measurement technique, Mean Reciprocal Rank (MRR), Precision, Mean Average Precision (MAP), Discounted Cumulative Gain (DCG) and Normalized DCG (NDCG). The experimentation is performed on a dataset acquired after pre-processing of the results collected from initial few pages retrieved for a query by the Google search engine. Based on the type and amount of in-hand domain expertise 30 queries are designed. The extensive evaluation and result analysis are performed using MRR, [email protected], MAP, DCG, and NDCG as the performance measuring statistical metrics. Furthermore, results are statistically verified using a significance test. Findings show that our approach outperforms state of the art methods by attaining 0.8666 as MRR value, 0.7957 as MAP value. Thus contributing to the improvement in the ranking of web pages more efficiently as compared to its counterparts. 相似文献
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我国政府提出实施创新驱动发展战略,强调科技成果转化对提高社会生产力以及推动经济转型的重要意义.利用北京市GDP、社会固定资产投资及劳动力数量得出反映科技成果转化水平的技术进步率,建立向量自回归模型(VAR),对北京市政府采购额、高技术产业科技活动人员和技术进步率3个变量的动态关系进行实证分析.研究表明,北京市政府采购对技术进步率和科技活动人员增加的贡献度分别达20.78%、40.28%,科技活动人员增加对技术进步率的贡献度达15.82%.可见,政府采购科技创新产品可促进科技成果转化、推动科技创新;通过引进高技术人才,优先采购本国服务,将对科技创新产生显著推动作用.为此,北京市政府应提高本国科技产品采购比重;将取得我国永久居留权的国外人才纳入本国服务提供者的自然人范畴,以记点积分系统、移民职业清单制度创造更优越的环境引进国外高技术人才,推动我国科技创新成果的转化. 相似文献
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变译理论在一个新的学术维度上扩展了翻译理论的空间,丰富并构造了翻译学上的新的理论形态。然而,反观其理论表述,笔者发现构成变译理论自身结构的某些基本原则与具体细节存在颇多不恰当与疏漏之处。本文仅以书中的两个命题——变译理论的应用范围的界定以及如何处理翻译作品中的所引为研究个案,借此阐明笔者对变译理论的个人理解并兼与著者就其存在的某些理论分歧予以商榷。 相似文献
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文章定义了广义等距曲线的矢量表达式,具体求出了广义等距曲线的曲率、弧长等一系列分析性质,使广义等距曲线在应用时更加方便. 相似文献