多特征融合的视频镜头分割

针对传统镜头分割算法特征单一、分割效果较差等问题，提出了一种多特征融合的视频镜头分割算法。首先，通过建立一种优化模型，融合空间差异度量和感知哈希度量两种重要特征，构造一种镜头边界区分能力更强的镜头边界检测特征，即像素差异度量；其次，结合直方图差异度量，形成有效的镜头边界检测策略，以便更加准确判断是否发生镜头切换。实验结果表明，与传统算法相比，所提算法取得了较好的分割效果，具有较高的查准率和查全率。     

A secure hash function based on feedback iterative structure

Rapid growth of internet data has created enormous security challenges on authenticity, availability and integrity protection of these outsourced data. Hash function is one of the main solutions to face these challenges. This paper proposes a feedback iterative structure of hash function which utilises the variable feedback to resist attacks. Furthermore, to accelerate message diffusion, two novel modules are designed, one for iteration and the other for truncation. Experimental results show that the proposed hash function can effectively resist existing attacks. Moreover, comparing with other existing hash functions, it displays better on statistical performance, collision resistance and avalanche.     

Time compression (dis)economies: An empirical analysis

Research Summary: To investigate time compression diseconomies (TCD), this study estimated time–cost elasticities using 459 oil and gas global investment projects (1997–2010). Results show that the average cost of accelerating investments is negative: a firm could cut $6.3 million in costs of a single project by accumulating asset stocks 1 month faster. About 88% of the projects exhibit negative time–cost elasticities with over 39% of unrealized economies of time compression. Only 12% of the projects are subject to TCD. These time inefficiencies or frictions do not negate the existence of TCD, but suggest they are less prevalent than assumed in the literature. Management experience, R&D investment, firm size, economic development, and political stability are shown to be associated with greater time compression efficiency. Managerial Summary: How fast should firms invest? The conventional view is that acceleration increases market revenues but also inflates costs. However, there is no recent empirical evidence of this tradeoff. Our article systematically investigates the costs of compressing time in investment projects. Results show that most firms in the oil and gas industry are significantly time inefficient in their operations. Specifically, by accelerating investments, firms would also substantially decrease costs. We estimate the magnitude of these time inefficiencies for specific oil and gas industries and firms and study which strategies might mitigate this problem. This fine‐grained analysis should help firms assess their financial incentives to accelerate projects and prove informative to stock market analysts’ valuations of firm investment timing.     

基于“三螺旋”理论的数字出版技术技能型人才培养机制创新探究

面对数字化生态的新现状及政府引导扶持的空前力度，数字产业迎来了新的历史发展关键时期，数字出版技术技能型人才在需求增速提升的同时，其培养机制亦需要做出相应的调整，以适应新形势、把握新机遇。基于”三螺旋”理论，分析了 “产学政融合”培养模式对比传统产教融合模式的特点与优势，并提出了对应的实施策略与路径，为我国数字出版专业人才培养提供了新的参考思路。     

“一带一路”背景下旅游物流融合发展研究

“一带一路”战略的提出极大地推动了旅游与物流业的发展,也给旅游物流产业带来良好的发展机遇。在这样的背景下,文章通过文献梳理研究发现,旅游物流发展前景广阔,但依然存在先进物流技术融合、资源整合、发展思路及综合人才等问题,建议从完善法律法规、加强人才培养、发展绿色旅游物流及构建信息平台等方面推动旅游物流产业发展。     

自适应干扰抵消系统的陷波带宽压缩方法

自适应干扰抵消系统会对邻近有用信号造成抵消效应。针对独立通信平台短波大功率模拟调制干扰，从频域和时域的角度分析了干扰抵消系统造成有用信号衰减和存在陷波带宽的机理，提出了一种能消除有用信号衰减的陷波带宽压缩方法。该方法通过实时检测抵消剩余载波信号大小并与设定值比较，通过比较结果来锁定和释放干扰抵消系统相关器输出的权值，从而维持干扰抵消系统稳态时的恒权值，保证了有用信号不被抵消。仿真结果表明，所提陷波带宽压缩方法可有效保护有用信号不被衰减。     

采样率对宽带LFM信号数字脉压的影响

宽带LFM(线性调频)信号数字脉压中，当采样率不能取得足够高时，在不同的采样率下脉压输出结果将发生变化。此时，采样起点和多普勒频率的变化也将影响脉压结果，并且两者对脉压结果的影响有一定的等效关系。通过较全面的仿真，为宽带LFM信号数字脉压的工程应用中合理选择采样率提供了参考。     

一种辐射源多特征数据关联的新方法

提出了一种辐射源多特征数据关联的新方法，对数据关联的相似性度量进行了讨论，给出了一种新的多特征参量统计相似性度量，并用谱系聚类法作数据关联，对所得关联结果进行了统计检验，计算机仿真结果证实了本方法的有效性。     

关于航空文化产业发展的融合融通融资探讨——以西安航空基地为例

航空文化是整个文化事业的组成部分,是文化向航空经济渗透和延伸的载体和“集合”。研究表明,航空文化与科技、旅游业的融合,提出了深度开发和全域旅游的商业模式;与保税区的保税融通,提出了文化保税政策设计和“摸石过河”试验;与金融系统的文化融资,提出了建立政府发展基金和融资新思路。     

蓖麻油酸与3种制取方法

蓖麻油酸由蓖麻油制取,是很重要的化工原料,本文介绍了它的理化性质、化工用途、规格标准、三种制取方法,其中对三种制取方法作了详尽论述,包括制取原理、工艺与设备、操作程序等.