Subjects: Library Science,Information Science >> Information Science submitted time 2017-10-11 Cooperative journals: 《数据分析与知识发现》
Abstract:【目的】通过大学生志愿者进行网络谣言传播的控制实验, 研究不同话题网络谣言传播中网民群体的态度演变动因和规律。【方法】采用问卷调查, 记录不同谣言传播过程中实验对象的态度与行为数据, 使用数据挖掘分类算法分析网民态度演变的共性与差异。【结果】研究结果表明, 网民传播谣言具有验证特性, 谣言的内容影响网民传播的媒介, 网民观点交互随群体一致性动态变化。影响网民态度及其演化的主要因素包括初始认知、群体行为、信息获取和交流渠道, 网民的态度演变率与网络谣言的内容等相关指标关联度较低。【局限】研究对象局限于大学生群体会影响研究结论的普适性。【结论】将实验研究和数据挖掘技术结合对网络谣言进行研究,为网络谣言的模型研究提供数据参考。
Subjects: Library Science,Information Science >> Information Science submitted time 2023-04-01 Cooperative journals: 《图书情报工作》
Abstract: [Purpose/significance] This paper studies the satisfaction of public digital cultural services, in order to promote the supply side of services to further connect with the demand side.[Method/process] According to the four standards of supply and demand adaptability theory, this paper constructed the satisfaction evaluation model of public digital cultural services. The data were collected in the form of questionnaire, and the model was tested by confirmatory factor analysis and path analysis. At the same time, the results of the scale were statistically analyzed.[Result/conclusion] The research shows that the four indicators of the theory of supply-demand adaptability, such as relevance, accessibility, quality and adaptability, have a significant positive impact on user satisfaction, and the scores of these four indicators are low. There is still a large room for improvement in the supply-demand adaptability of public digital cultural services.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2019-04-01 Cooperative journals: 《计算机应用研究》
Abstract: Categorical features always exist in the dataset and coding them is a key issue for solving problems efficiently by machine learning models. One-hot coding is a wide accepted method to convert the features into feature values, and however it attracts sparse space and meaningless value after coding. To improve the coding performance, a novel coding method based on conditional probability after dividing the features into zones, which is called CZT coding (Conditional-probability-based Zone Transformation coding) , is designed. The CZT coding calculates the conditional probability of each feature and then divides the features into several zones and finally coding the features in each zone. This paper mathematically proved that compared with the state-of-the-art method - one-hot coding, CZT coding reduces the code length by at least the mean of feature spaces and the issue switches into an easier one after CZT coding for the following machine learning model. Finally, using the same neuron network as the classifier, the performance of CZT coding and one-hot coding is compared by using the titanic dataset, and the result is that CZT coding makes the classifier performs better both on the accuracy and steadiness.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2019-05-10 Cooperative journals: 《计算机应用研究》
Abstract: It attracts lots of attention in the field of object trajectory detection that detectors always receive several geographical locations without any other information about the targets, and furthermore it comes into a problem to use the geographical location information received by the sensors to reconstruct the trajectories of each target as well as to distinguish the targets in each frame, which is called multi-target trajectory recovery and can be solved by Deep Reinforcement Learning (DRL) . A trajectory osculating circle (TOC) reward function is implemented based on the mathematical model of the direction and trajectory curvature according to the peculiarity of trajectories in actual. Firstly, the issue of the multi-target trajectory reconstruction is switched into a model which can be appropriate for DRL. Then, DRL is tested with the proposed reward function. Finally, a mathematical derivation and physical interpretation of the proposed TOC reward function is introduced. The experimental result shows that with the guidance of the TOC reward function, DRL can reverse the trajectory effectively, and the trace corresponds well with the actual trajectory.
Subjects: Geosciences >> Space Physics submitted time 2017-03-10
Abstract:目前对火星CH4气体的探测是探索火星生命的一项重要手段,圈定出火星表面CH4源区的位置可为将来火星生命的探索选取合适的目标点。本文在对火星CH4气体共振散射进行探测的基础上,通过数值模拟的方法对火星CH4气体的空间分布进行了反演。反演结果能再现模型的密度分布,辨认出CH4气体密度分布较为稠密的区域,从而可以确定出火星表面CH4源区的位置。
Peer Review Status:Awaiting Review
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-28 Cooperative journals: 《中国科学院院刊》
Abstract: The rapid development of information technology has unprecedentedly created a prosperous cyber society and greatly enhanced productivity facilitated by social interaction. At the same time, many problems emerge in the cyber society, such as telecom fraud, privacy leakage, Internet pollution, and algorithmic discrimination. The problems bring new challenges to social order and security. In order to find the way of cyber society governance and promote the modernization of national governance, this paper first presents the analyses on the new problems encountered in the cyber society in three typical scenarios, i.e., identity governance, behavior governance, and algorithm governance, as well as their risk to the economy, society and security. Furthermore, this paper lists the key challenges for the problem governance, and presents technical countermeasures for modern governance of cyber society from three levels of chip, system, and algorithm.