Novel high torque bearingless two-sided rotary ultrasonic motor

Applications are limited at present because the currently available ultrasonic motors (USMs) do not provide suffi-ciently high torque and power. The conventional travelling-wave USM needs the bearing to support, which required lubricant. To solve the above problem, a bearingless travelling-wave USM is designed. First, a novel structure of the two-sided USM consisting of a two-sided teeth stator and two disk-type rotors is designed. And the excitation principle of the two-sided travelling-wave USM is analyzed. Then, using ANSYS software, we set up the model of the stator to predict the excitation frequency and modal response of the stator. The shape of the vibration mode was obtained. Last, the load characteristics of the USM are measured using ex-perimental method. The maximum stall torque and the no-load speed were obtained. The results showed that the characteristics of the two-sided USM are better than those of the conventional one-sided USM.     

基于双边市场的手机操作系统平台竞争策略——以Android操作系统平台为例

在移动互联网快速发展的今天,手机操作系统扮演着越来越重要的角色.作为联系终端用户和移动互联网的桥梁,手机操作系统已经被看作是移动通讯领域的核心.而移动操作系统的本质是平台.本文以双边市场理论为基础,分析了手机操作系统平台的特征,构建了手机操作系统平台的双边市场结构.并以自面世以来就获得巨大成功的Android手机操作系统平台为例,分析了Android平台的一系列策略性行为.     

一种电子商务中买卖双方交易匹配的决策方法

针对电子商务中买卖双方交易匹配问题,文章将主体给出的多粒度语言评价信息转化成三角模糊数形式,运用逼近理想解法计算主体综合评价与理想评价的相对贴近度,并以其表示匹配主体的满意度。构建综合考虑匹配主体满意度一致性和最大化的优化模型,求解该模型获得匹配结果。通过实例说明所提方法的可行性和有效性。     

基于图模型的供需匹配决策研究

从分析供需匹配之间存在的冲突入手,提出一种基于图模型冲突分析法来求解供需匹配问题的思路。首先在图模型视角下给出供需匹配问题的研究框架,分析不同类型的供需匹配问题,设定决策主体和决策策略;然后讨论不同匹配类型下的状态约简、偏好表达,进行稳定性分析;最后通过应用案例,将图模型法与群决策匹配算法进行对比分析,验证图模型求解供需匹配问题的有效性。     

论双面信息策略在突发公共事件传播中的应用

该研究基于归因理论、疫苗理论、锚定理论,结合相关文献分析了在突发公共事件传播中运用双面信息策略的必要性和可行性,阐述了双面信息策略在突发公共事件传播中提高可信度及抵制谣言的作用,探索具体的实施策略。该研究为突发公共事件的传播和谣言的抵制研究奠定了一定的理论基础,并能为相关应用研究提供理论指导。     

诱导小鼠产生脑缺血耐受的时间窗探讨

目的：探讨诱导小鼠产生脑缺血耐受的时间窗。方法：采用两次结扎小鼠双侧颈总动脉方法造脑缺血耐受模型,通过观察不同预处理诱导时间窗下小鼠脑组织形态的变化,探讨诱导小鼠脑缺血耐受产生的最佳时间窗。结果48h、168h、240h诱导组、缺血再灌注组小鼠脑神经细胞病理改变明显加重,120h诱导组脑缺血耐受较其他实验组好。结论：120h诱导时间窗为比较合适的脑缺血耐受时间。     

Spatial data infrastructure management: A two-sided market approach for strategic reflections

The recognition of a spatial data infrastructure (SDI), as a two-sided market, leads the way to an innovative approach for analysing the strategies used to bring two groups of users into interdependent markets. The literature derived from the recent industrial organisation is rich in theoretical models, aiming at the study of price structure and product design, which maximise the participation of the groups, the profits of the firms, and the value created for the entire ecosystem. The current paper interprets and adapts the theoretical model of the two-sided market in order to fit the case of a SDI. The purpose is to highlight the relevance of a two-sided market approach for analysing a SDI dynamics. The focal research question is how spatial data infrastructure, through a platform management process, can transition from a government-funded entity to a self-sustaining operation. The analysis relies on the specific case of the GEOSUD SDI, focusing on strategies ensuring the interest of image-based application developers and satellite image users. The results show that the theory of two-sided markets brings complementary elements for SDI development strategies, by proposing a framework of reasoning, which not only allows for a better understanding of the outflows already established, but also provides tools to accompany the strategic reflection of public institutions and entrepreneurs, who tend to support the uses of data and services derived from remote sensing.     

The Value of Scholarly Journals in a Two-Sided Market

Two-sided markets are a relatively new economic concept that has relevance for scholarly communications. Scholarly journals, as well as bundles of scholarly journals, can best be understood as examples of two-sided markets, and journal-pricing issues can best be examined using this concept. Serials librarians, electronic resources librarians, and scholarly communications specialists should incorporate two-sided markets into their understanding of the shifting journals environment.     

Electronic platforms and two-sided markets: A side-switching analysis

We define electronic platforms as two-sided markets in which two groups of agents – sellers and buyers – can switch from one side of the market to the other. Using a duopoly model, we interpret equilibrium fees and profits in terms of rewards and penalties, relative to the equilibrium without side-switching. We establish that if the group with the highest side-switching probability has the lowest externality parameter, platforms make more profit with side-switching. It is also shown that agents' heterogeneity is favorable to platform profitability.