A Basic Study of User Utility Maximizing Content Retrieval from Information Networks

This paper proposes some basic methods of content search yielding high user utility or user's satisfaction from numerous information sources scattered over large‐scale networks. In these methods, the search policy is decided by the estimated user utility gain and/or current user utility for each search action, and the most favorable combination of information sources and search content items is selected so as to enlarge the total user utility of the entire search activity. In addition, we evaluate the efficiency of the methods by computer simulations, in which we specify the network topology, user utility functions, probabilities of existence of the search content items in each information source, and so on, apply the proposed methods and other methods for comparison, and compare their aggregate utility gains as an estimation index. The proposed methods are found to achieve good performance in general and an index value about 2.45 times that of ordinary search is observed in an extreme simulation scenario. We discuss the pros and cons of the proposed methods for all the simulation scenarios.     

Topological-based bottleneck analysis and improvement strategies for traffic networks

A method is proposed to find key components of traffic networks with homogenous and heterogeneous topologies, in which heavier traffic flow is transported. One component, called the skeleton, is the minimum spanning tree (MST) based on the zero flow cost (ZCMST). The other component is the infinite incipient percolation cluster (IIC) which represents the spine of the traffic network. Then, a new method to analysis the property of the bottleneck in a large scale traffic network is given from a macroscopic an...     

Design and interpretation of cell trajectory assays

Cell trajectory data are often reported in the experimental cell biology literature to distinguish between different types of cell migration. Unfortunately, there is no accepted protocol for designing or interpreting such experiments and this makes it difficult to quantitatively compare different published datasets and to understand how changes in experimental design influence our ability to interpret different experiments. Here, we use an individual-based mathematical model to simulate the key features of a cell trajectory experiment. This shows that our ability to correctly interpret trajectory data is extremely sensitive to the geometry and timing of the experiment, the degree of motility bias and the number of experimental replicates. We show that cell trajectory experiments produce data that are most reliable when the experiment is performed in a quasi-one-dimensional geometry with a large number of identically prepared experiments conducted over a relatively short time-interval rather than a few trajectories recorded over particularly long time-intervals.     

多输入多输出—非正交多址接入系统融合用户调度的下行波束赋形设计

针对多输入多输出—非正交多址接入（MIMO-NOMA）技术中用户间干扰较大的问题，提出了一种融合用户调度的波束赋形（BF）算法。首先，在进行用户调度时，为了同时兼顾簇内用户干扰和簇间用户干扰，根据各用户信道的差异性，利用L1-范数正则化方法对所有用户分组情况进行初步稀疏化处理，进而从各用户信道相关性角度出发，将信道相关性大的两个用户分为一簇；其次，结合部分发射功率控制（FTPC）策略实现簇内用户功率分配；最后，根据和速率最大化准则构建一目标优化函数，进而利用连续凸逼近（SCA）算法对其进行求解，以获得波束赋形矩阵。理论分析和链路仿真表明，与传统的正交多址接入技术相比，在系统容量方面实现了84.3%的提升；与传统的相关性用户分簇方法相比，在公平性方面实现了20.2%的提升。实验结果表明，该方案不仅有效地抑制了簇内用户干扰和簇间用户干扰，同时，又保证了用户间的公平性。     

住宅小区用户驻地网共建共享方案研究

在多运营商全业务竞争环境下,对住宅小区用户驻地网的共建共享问题进行分析研究,提出住宅小区用户驻地网的建设思路、网络分层及共建共享方案,对于多运营商和谐有序竞争、落实共建共享、避免重复建设政策有一定的借鉴作用和指导意义。     

A study on Cationic Surfactants as Drag-Reducing Additives

In this study, we investigated the influence of the number of ethanol (EO) groups of cationic surfactants having one oleyl group on the drag-reducing effect (DR effect). Also the effect of mechanical pumping power on DR effect was experimentally investigated using two experimental setups, a circulation system (with pump) and a pressurized once-through system (without pump). The concluding remarks obtained in this study are: 1. The DR effect strongly depends on the re-formation rate of micelles disrupted mechanically. 2. When increasing the number of EO groups of the DR surfactants from 0 to 2, the available temperature range of large DR effect was shifted lower. But the DR surfactant having three EO groups (EO-3) barely exhibited the DR effect even at the low temperature. This is because the big hydrophilic head of EO groups probably delays the re-formation of micelles disrupted by pumping power. 3. The DR effect was more liable to be influenced by pumping power with a decrease in temperature. This is because it takes a long time to re-form micelles disrupted by pumping power at low temperature.     

智能手机操作系统群雄并起

近年来,随着全球移动数据业务使用量的迅猛增长,智能手机销量不断攀升。代表不同市场阵营的智能手机操作系统竞争日益激烈。笔者在回顾市场上主流操作系统形成现今市场地位的历史原因同时,对其未来的发展机遇逐一作了分析,在此基础上,对未来智能手机操作系统的市场格局做出了预测。     

实钻井眼轨迹视投影长度的计算方法

垂直剖面图是显示实钻井眼轨迹的重要方法,其关键在于计算实钻井眼轨迹在设计柱面上的投影曲线。根据几何学原理得到了投影计算的一般方程。并对井段曲线类型为直线、圆柱螺线、圆弧等几种常用情况进行了详细的分析,得到了投影点参数的计算公式。计算实例表明。在实际钻井过程中,利用视投影长度绘制三维井眼实钻轨迹的垂直剖面图可以直观地对比实钻井眼轨迹与设计井眼轨迹的吻合程度,从而起到较好的指导井眼轨迹预测和控制的作用。