京津城际轨道设标网高程测量

针对高速铁路轨道设标网高程测量精度要求高、点位分布密集的特点,提出了Z字型观测路线方案,为提高测量精度从测站、测段,测量环境等方面提出了质量控制方案。京津城际高速铁路实测结果表明,本文提出的方法合理有效,满足无碴轨道铺轨和检验精度要求,达到了预期目的。

凉水河特大桥轨道基准网测设及平差计算方法

简单介绍了无砟轨道基准网及其GRP点测量及数据平差计算方法,针对京津城际凉水河特大桥轨道基准网测设中存在的问题提出控制措施和解决办法,并取得了较好结果,对以后的无砟轨道测量方法具有积极的指导和借鉴意义。

Study on Classification of Personality-Based Brand Archetype from the Perspective of Internet

Due to the rapid development,Internet has become the main field for brand building.Under this circumstance,the image of the brand is always consistent with the consumers' perception.Therefore,this study uses the method of text mining of search engine to explore the categories of brand archetype based on Brand Personality Theory from the perspective of Internet.The results find that 12 brand archetypes,including caregiver,sage,hero,innocent,dominator,creator,vitality,explorer,stylish woman,lover,cooperator,and vogue gentleman,have a high degree explanation.Deeper study uses case study to verify the reasonability and effectiveness of the classification standard.

Performance analysis of QoS routing protocol for WiMedia networks

Though the WiMedia supports higher data rates than other WPAN technologies,a WiMedia device cannot reach other devices that are separated from it by more than 10 m,which is the typical limited transmission range of the WiMedia protocol.In this work,we propose a multi-hop QoS routing protocol to enable WiMedia devices to transmit real-time data to devices that are located out of the transmission range.The proposed routing protocol is a hybrid algorithm,which mixes the table-driven and on-demand routing algorithms,searching one or more routes according to the number of hops to a destination device.WiMedia MAC is potentially capable of learning the existence of neighbor devices by using a beacon frame.By utilizing the neighbors' information,all devices can create routing entries for devices within 2-hops periodically.For devices beyond the 2-hop range,the newly designed on-demand routing algorithm is applied to multi-hop routing.If a routing entry for a destination device is not listed in the routing table,the source device sends a request packet to 2-hop range devices which could be found in the routing table.Since every device maintains routing entries for 2-hop range devices in the routing table,the request packet is replied in advance before its arrival at the destination device.Also,to decide the optimal route for a destination device,the number of medium access slots(MASs),received signal strength indicator(RSSI)and hop count are utilized to establish a QoS-enabled routing table.We perform ns-2 simulation to investigate the performance of the proposed routing protocol with AODV and DSDV.The simulation results show that the proposed protocol has better throughput and lower overhead than other protocols.

Impact of and adaptation strategies for sea-level rise on Yangtze River Delta

The Yangtze River Delta characterized by a dense population and a rapidly developing economy is highly vulnerable to sea-level rise. The data from the China Oceanic Information Network and the Zhejiang Provincial Hydrology Bureau are used to analyze sea-level rise. The rate of sea-level rise in the delta was 2.4 mm per year in 1981-2015. The annual sea-level at Daishan, Dinghai, and Dongtou stations in the south wing of the delta were 4.3, 3.1, and 5 mm per year respectively over the same period. The 10-year averaged results at each station also indicate a perceptible trend of sea-level rise. Sea-level rise is contributed to a larger proportion of intensified erosion, ranging from 3% to 14% in the delta. Meanwhile, the 100-year return period of tidal level has decreased to the 50-year rank at Dongtou and Dinghai stations. Moreover, the arrival time of tidal bores at Yanguan is 4 min earlier under sea-level rise of 0.145 m than that of 0 m. The height of tidal bores and the velocities at the surface and bottom layers have an increase under sea-level rise. The maximum increases of high and low tide levels are 0.122 m and 0.016 m while the maximum increases of the velocities at the surface and bottom layers are 0.07 m s^- 1 and 0.05 m s ^-1, respectively. Sea-level rise will bring about the damage of seawall, thus the design standard of constructing seawalls should adopt a higher level to minimize the associated risks in the Yangtze River Delta and its south wing.

Construction and Upgrade of Urban Power Grids:Achievements and Tasks

The significant achievements in construction and upgrade of China’s urban grids in the past two years and more are enumerated with respect to scale of grids, configuration of medium-and high-voltage grids, technical and localizing level of equipment, as well as social and economic benefits. At the same time, the new tasks for the year 2001 is put forth for volume of investment to be completed, projects progressing and operating benefit indexes, etc.

Energy-Efficient Target Channel Sequence Design for Spectrum Handoffs in Cognitive Radio Networks

Cognitive radio is considered as an efficient way to improve the spectrum efficiency. As one of its key technologies,spectrum handoff can guarantee the transmission continuity of secondary users(SUs). In this paper,we address a new and more generalized spectrum handoff problem in cognitive radio networks(CRNs),by considering simultaneously energy efficiency,multiple spectrum handoffs and multiple channels. Furthermore,effects of the primary users'(PUs')arrival and service rate on the target channel sequence selection are also considered. In order to obtain the energy-efficient target channel sequence,we firstly analyze the energy consumption and the number of delivered bits per hertz in the spectrum handoff process,and formulate a ratio-type energy efficiency optimization problem,which can be transformed into a parametric problem by utilizing fractional programming. Then,we propose an algorithm combining dynamic programming with bisection(DPB)algorithm to solve the energy efficiency optimization problem. Our simulation results verify that the designed target channel sequence has better performance than the existing algorithms in terms of energy efficiency.

Political Advertising and Propaganda Within Spiral of Silence-Agenda Setting Theory

Political communication is an interactive process by which politicians transmit information and political discourse to voters and receive feedback through media. This communication process is a two way process of communication between politicians and voters by which, on the one hand, politicians transmit their thoughts and wills to voters, and on the other hand voters communicate their opinions to politicians, after interpreting, in different ways, the messages that they received. The key objective of political communication is to persuade or influence and cause voters, who are the target audience, to vote for a particular party by convincing them. In order to ensure the smooth operation of political communication processes it is essential that the parliament, government, political parties, non-governmental organizations, environmentalist groups and pressure groups also actually take part in this process The decisive and transformative power of mass media and advertising phenomenon on the political systems has grown to become more and more influential in the recent years. The use of information considerably increases in line with the increase in the use of propaganda. No doubL this information age has turned the world into ＂a universal village＂. On the one hand, the concentration in media and on the other hand rapid developments in Internet technologies expose societies to the bombardment of messages. Being exposed to or bombarded by numerous varieties of messages in their daily lives lead to the creation of variabilities and instabilities in individual＇s behaviors. Accordingly, political organizations while trying to convey messages to masses through political communication and advertising have to deliver systematic, comprehensible and influential messages by taking the advantage of visualization as much as possible.

Research and Analysis of the Parallel Computer Network Reliability

With the continuous development of network communication technology and computer technology, parallel computer network applications becoming more widely, its reliability has attracted more attention on researcher. This paper gives a introduction to a simple computer network, given the reliability of the design criteria for computer network analysis, and finally through the examples to illustrate the computer network hardware and software reliability.

Research on Interactive Learning and Teaching based on Computer Network

This paper analyzes the basic interactivity connotation of network teaching from the interactive definition, function, types and level etc., and established the interaction quality evaluation index system from the four angles between student and media, the course content, teacher and peer interaction. Similarly, network instruction interaction also needs to carry on the design from the perspective of instructional design, and take full advantage of the Internet, and finally achieved good network interaction effect. Practice shows that, research on network interactive strategy significance.