基于DAG方法的一个新的查询应答驱动路由协议与移动网络可达性分析(IJCNIS-V5-N12-7)
I. J. Computer Network and Information Security, 2013, 12, 53-59
Published Online October 2013 in MECS (https://www.wendangku.net/doc/ae2644929.html,/)
DOI: 10.5815/ijcnis.2013.12.07
A New QUERY-REPLY Driven Routing Protocol with Reachability Analysis for Mobile Networks: DAG based Approach
Paulami Dey, Parag Kumar Guha Thakurta
National Institute of Technology, Durgapur, Durgapur-713209, West Bengal, India
paulamidey77@https://www.wendangku.net/doc/ae2644929.html,, parag.nitdgp@https://www.wendangku.net/doc/ae2644929.html,
Abstract — An efficient Query-Reply based routing protocol for mobile networks is proposed in this paper. The alternative paths have been generated between source and destination nodes in the network. A Directed Acyclic Graph (DAG) is developed on the basis of selected right path among the alternatives. The reachability relationship is established on DAG and subsequently it introduces a proactive routing approach. As a result, the time complexity for the proposed routing method is reduced to a desired extent. The simulation studies confirm the improvements of the proposed model over the others. Index Terms — Directed Acyclic Graph, Reachability relation, QUERY-REPLY, Routing
I.I NTRODUCTION
In recent time, rapid escalation of cellular telephony is combined with a need for improved and efficient routing strategies. A powerful messaging pattern with a two way conversation over a channel is also required at the same time. During congestion in the network, one of such strategies known as Call Admission Control (CAC) is used to restrict the amount of users utilizing the network. The rest of the users are not permitted to any slot during this period [1]. Subsequently, Quality of Service (QoS) can be ascertained for the admitted users. Hence, it establishes two near contradictory prerequisites – propagating packets as well as ensuring Quality of Service (QoS) when all users are sending packet at the same time [2].
There are various routing strategies used in mobile networks till date. Some of those have used request-reply approach to obtain routing paths. The Directed Acyclic Graph (DAG) [3] approach is used to predict the nature of routing in advance. One of DAG based approach in [4] provides a reliable routing path in terms of multiple segments between source and destination nodes. With effect, a group of routing protocols for a network of processes is presented in [5] to route data to each member of the family. A request-reply based method in [6] develops a DAG to present a framework for loop-free on demand routing. Another routing method [7] is operated by controlling the request and response zones of network nodes during the route search process in order to reduce the routing overhead and network load. Again, a DAG based routing method [8] was introduced to support various path direction among the nodes in the network. A different routing model proposed in [9] results improved communication delay with packet delivery. The independent DAGs were developed [10] to compute independency on links and corresponding nodes. In this context, a research in [11] establishes a reachability relation which subsequently reduces the network traffic with high attainability. To improve sustainability of the network against failure, a proactive routing method has been discussed in [12].
The model proposed in this paper provides a new routing protocol for mobile networks. The work begins with representing a network to its equivalent graph GG. The alternative routing paths have been generated between source and destination nodes in GG through QUERY-REPLY packets. The right path among the alternatives has been selected following certain criteria defined on the model. Hence a Directed Acyclic Graph (DAG) GG′ is developed from the right path. Further it establishes a reachability relationship between these two nodes. Thus a proactive routing approach has been introduced to reduce the time complexity for communication to the desired extent. In addition, an improved scalability is obtained with the proposed work for larger number of the nodes in the network. The improvements of the proposed model over the other approaches are discussed through the experimental results. The rest of the paper is organized as follows. The model proposed here is described in section II. The experimental results for the proposed model are discussed in section III. The advantage of the work is concluded with its future scope in section IV.
II.P ROPOSED M ODEL
A. System Model and assumptions
The standard cellular structure [13] for mobile networks in Fig. 1 (a) is considered as the layout of the proposed system. Each cell in the layout is represented as CC pppp, where pp denotes the radial distance (rr) from mobile switching centre (MT) and the sequence number
54 A New QUERY-REPLY Driven Routing Protocol with Reachability Analysis for
Mobile Networks: DAG based Approach
of a cell in a specific radial distance (rr)is denoted by pp. This structure is alternatively represented here as a graph GG=(nn,ee), where nn is the set of nodes denoting base stations (BSs) and mobile switching centre (MT)
participating in communication, and ee denotes the set of edges representing the connectivity among the nodes. The equivalent GG for rr=3 as a prototype is shown in Fig. 1(b).
Figure 1: Representation of mobile networks (a) Cellular layout,
(b) Equivalent graph structure.
The flexibility in the structure of GG is maintained in such a way that the cccccccc (ii) ?ii∈nn due to handoff and cabling cost (cccccccc cccc (ii,jj)?ii,jj∈nn) can be minimized. The detailed outline for such minimization is described as follows.
A location updates strategy [14] which includes mobility and call arrival pattern is applied when mobile users cross a position area (PA) boundary. Then two factors related to such updating are considered as– (i) the pprrccpp(PPPP(ii)) is defined as the probability of the user being located in PPPP(ii) and (ii) the ccaaaaCCcccccc(ii) is expressed as the average cost in PPPP(ii) with assuming call arrival following Poisson distribution. Thus the minimization of cost function (cccccccc (ii) ?ii∈nn) is presented as follows. ccppjj ee cccc ii aa ee: mmii nn ii mm ii mm ee?pprrccpp?PPPP(ii)?.ccaaaaCCcccccc(ii)
nn
ii=1
(1) ccssppjj ee cccc cc cc pp ii=?1, ffccrr ssppuucccc ee ii nn PPPP(ii)
0, cccc?eerreeii cc ee(2) In (2), the update per user is represented by a binary string {pp nn ,.....,pp1}?ii∈nn.
Generally, the perpendicular bisectors for each edge in a symmetric hexagonal cell intersect at a fixed point. The placement of a BS as a node (nn) in GG at that fixed point reduces the cabling cost [15] (cccccccc cccc(ii,jj)?ii,jj∈nn) rather than placing it in any other position within the cell. Thus the minimization of the factors including cccccccc(ii)?ii∈nn and (cccccccc cccc(ii,jj)?ii,jj∈nn) are dependent on placing a node (nn) in a cell.
B. Problem Statement
The problem addressed in this work can be stated as – given a GG=(nn,ee), find a Directed Acyclic Graph (DAG) (GG′=(nn′,ee′)) obtained from right path pp (ii,jj), among multiple valid routing paths (PP:?pp (ii,jj)∈PP) generated by applying a procedure on GG, such that GG′ presents a reachability relation between ii ccnnuu jj,ee?eerree ii,jj∈nn.
For instance, the reachability relation between ii and jj provides knowledge of a legitimate connection guaranteeing confirmation of data flow which subsequently reduces the time complexity of routing. However, the main hypothesis considered over the problem is presented next.
C. Main Hypothesis
By using GG, with its corresponding ′ffccrr ccaa aa (ii,jj)∈nn, it is possible to minimize the routing time with the help of rechability relation between ii and jj.
Before describing the detailed framework of the proposed model, some useful terminologies with respect to the model are defined as follows.
D. Terminologies used
(a)QUERY and REPLY Packets: Two packets named as QUERY and REPLY are used by the nodes to send data as well as receiving acknowledgement respectively.
(b)Node’s unique ID: Each node in the network is identified with its unique ID to identify specific source and destination respectively.
(c)Hop-metric: Two Hop metrics known as H_Query and H_Reply are associated with each node in the network to find the valid routing paths between specific source and destination respectively.
E. Steps of the Proposed Work
(i) Generation of Routing Paths:
The set of routing paths (PP) have been generated as a result of execution of the Routing Path Generation algorithm. Initially, the source node (nn SSSS) broadcasts the QUERY packet with the unique ID (II II nn IIDD)
of the
destination node(nn IIDD). Here, the H_Query values are initialized with the following instances.
H_Query=?0, ffccrr nn IIDD
NNNNNNNN, cccc?eerreeii cc ee (3)
The destination node (nn IIDD) having H_Query value as
0 would receive the QUERY packet. After that, nn IIDD sets
its H_Reply value to its H_Query value. Further
nn IIDD sends a REPLY packet as an acknowledgment along
with its own H_Reply value and ID (II II nn SSSS) of nn SSSS. Each
intermediate node (nn RRDD) in the path receiving and passing
the REPLY sets its H_Reply value with incrementing
H_Reply from the previous nn RRDD by one. This process is
continued until II II nn SSSS matches with II II nn RRDD. The procedure
is described by the following algorithm 1.
Algorithm 1: Routing path Generation
Input: A graph GG=(nn,ee)
Output: A set of routing paths(PP).
Functions Used:
Broadcast_packet (Packet, II II nn IIDD): nn SSSS broadcasts
packet along with II II nn IIDD.
Receive_packet (Packet,nn IIDD): Node nn IIDD receives
the packet.
Send_packet (Packet, II II nn SSSS, (H_Reply) nn IIDD): Node
nn IIDD sends out the Packet along with its H_Reply value.
Method:
(ii) Selection of Right Path:
The right path pp (ii,jj)?ii,jj∈nn is selected among the
set PP by following rules.
Rule 1: If there are different (H_Reply) nn SSSS values for various routing paths(PP), then the right path pp (ii,jj)?ii,jj∈nn is with minimum (H_Reply) nn SSSS value. Rule 2: If there are more than one routing paths (P) obtained with same minimum (H_Reply)nn SSSS values, then the concept of logical clock [16] is used to evaluate the right one.
Thus the selection of the right path based on that concept is discussed as- a logical clock CC ii(cc) at a nnccuuee ii,( ii∈nn) in the GG is assigned as the timestamp of a specific REPLY sending event (cc). Again the REPLY passes through a node jj and subsequently this event (pp) is assigned a timestamp CC jj(pp). When ii sends out a REPLY through a path as an acknowledgement for the source node nn SSSS, then cc RRDDPPNNRR is assigned to the value of CC ii(cc). This REPLY passes through jj as said before. Hence the value of CC jj would become as follows.
CC jj=max?CC jj(pp),cc RRDDPPNNRR+uu?,uu>0 (4)
Where, uu is the communication delay between sending and receiving the packet.
In this way, there is a timestamp value CC SSSS at nn SSSS for every routing path. Subsequently these values are compared and the corresponding routing path with the minimum value among all is considered as the right path pp (ii,jj)?ii,jj∈nn.
(iii) DAG Representation:
A DAG is used in the proposed work to find the rechability relation between nn SSSS and nn IIDD- which subsequently reduces the time complexity for communication. To obtain a DAG from the selected right path, initially, nn SSSS with a min (H_Reply) nn SSSS value is considered as an initial condition. Then the nodes nn SSSS and nn IIDD are linked through a series of intermediate nodes (nn II NN) on the basis of sequential decrement of H_Reply values. This process is continued until H_Reply value becomes zero. The procedure is described by the algorithm 2 as follows.
Algorithm 2: DAG Representation
Input: A right path pp(ii,jj)?ii,jj∈nn. Output: A graph GG′=(nn′,ee′).Method:
Remark:If the entire network having a total number of nodes N is divided into m layers with nn aa nodes in each of them i.e.,∑nn aa mm aa=1=NN, then the number of possible DAGs over that network is expressed as follows:
II(NN)
=???….??(2[aa]mm?1aa=1
NN?mm+1?∑nn kk mm?1kk=1
nn mm=1
NN?mm+1?nn1
nn2=1
NN?mm+1
nn1=1
NN
mm=1
?2[aa?1]) (5)
(iv)Introduction of Reachability relation:
A GG′provides a directed path between nn SSSS and nn IIDD. Moreover, a transitive closure is developed as a result for such computation. Hence it introduces a reachability relation between nn SSSS and nn IIDD. The reachability relation obtained from GG’ represents a strict partial order among the nodes. Generally, the transitive reduction is an inverse process of transitive closure with maintaining the connectivity. In this context, the transitive reduction is unique for each GG′ in the entire network. Naturally the reachability relation represents the transitive closure of its edge set.
Let us assume GG′nn SSSS nn IIDD
kk=1, if and only if nn IIDD is reachable from nn SSSS through kk number of intermediate nodes. Here, if any path with GG′ss aa kk=1 is previously selected, then there is no need to check again that path as a candidate solution for further analysis. Thus it reduces time complexity for routing in advance. In such a way it enhances Quality of Service (QoS) for the network. A
salient feature of introducing such reachability relation is concluded with the following lemma. Lemma: Every reachability relation GG′ss aa kk has a unique transitive skeleton (σσ?GG′ss aa kk?) with polynomial time reduction.
Proof:There is an algorithm PP for constructing GG′which can be considered as an event XX. Henceforth reachability relation obtained on the basis of the transitive closure property from GG′ is considered as an event RR. Some properties are considered regarding these events as follows.
(a)Given an instance II xx of XX, PP produces an
instance II yy of RR.
(b)PP executes in polynomial time i.e., |II xx|.
(c)Answer to II yy yes iff answer to II xx is yes. Obviously, with satisfying these properties, it is concluded that RR is polynomial time reducible from XX
(XX≤pp RR).
F. Example of the Proposed Model
The performance for the proposed model has been analyzed with an example on the basis of Fig. 1(b). Here, n00and n34are considered as the source node and the destination node respectively. In between these two nodes, there are several possible alternative paths for communication. The five paths among these alternatives have been shown in Fig. 2 along with (H_Query, H_Reply) values respectively.
Figure 2: Alternative routing paths for n00 and n34 as source and
destination nodes
The path 3 shown in Fig. 2 is selected as the right path according to the criteria with least value of H_Reply, that is 3. Hence the DAG is shown in Fig. 3(a) and 3(b) based on path 3.
Figure 3: DAG representation: (a) QUERY and REPLY shown
separately, (b) Final GG′ for path 3
After the establishment of GG′ for path 3, the reachability relation has been introduced for nodes n00 and n34. In addition, the reachability relationship for the entire network (rr=3) is shown in Fig. 4 for the source as n00.
Figure 4: The reachability relations for n00 in rr=3
III.E XPERIMENTAL R ESULTS
This work is analyzed with MATLAB version 7.6.0.324 (R2008a) on processor Intel(R) Core(TM) i5-2410M CPU@ 2.30 GHz and RAM 4.00 GB. The following four performance metrics have been introduced here to evaluate the effectiveness for the proposed model.
A. Speedup Performance
The dedicated path has been established as a result of our proposed model. So, it is not required any searching delay to finding path for further analysis. In effect, the speed up is increased for the proposed model accordingly rather than traditional [17] one.
Speed up here is
calculated in terms of transmitting packet through a dedicated path. The behavioral representation between speed up performance and the number of nodes in the network is shown in Fig. 5.
Figure 5: Characteristic curve on speed up Vs. and the number
of nodes in the network
B. Quality of Service (QoS):
The delay is considered as the QoS metric for the proposed model. Generally, the delay is increased due to the lack of connectivity in end-to-end paths. In our work, the DAG provides the right path for communication in advance. Therefore, the QoS of the network is improved in the aspect of minimized delay. For example, the time cc required to traverse nn number of hops with a factor 1pp (nn )?, where pp (nn ) denotes QoS metric of the
network, is presented as pp (nn )= ?nn log nn . Here, the delay II is proportional to cc and it is expressed as a
function of (
1
?nn log nn
). Therefore, the improved QoS for the proposed model is obtained than the traditional approach [18] as shown in Fig. 6.
Figure 6: Improved QoS of the proposed model
C. Dropped Packet Rate (DPR)
It is proportional to the total number of packets dropped in the network. As the dedicated path established in previous, the possibility of dropped packet is less. Therefore, the reduced DPR results for increased transmission as shown in Fig.7.
Figure 7: DPR Vs transmission
D. Routing Overhead
Routing overhead is dependent on the total number of packets sent during the transmission. Due to the follow up of the proactive routing approach by the proposed model, the reduced routing overhead is obtained for the number of nodes in the network than the traditional approach [19] as shown in Fig. 8.
Figure 8: Reduced Routing overhead obtained for the proposed
model
VI.
C
ONCLUSIONS
The procedure of establishing the reach ability relation through DAG in mobile networks is described in this
work. This protocol reduces time complexity for the routing method. The importance of the transitive reduction is discussed to make it more significant in finding the right path. It increases the flexibility of dynamic call routing. Further study on extending this work to construct the routing table is in progress.
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Paulami Dey,passed B.Tech from WBUT, India in 2011. She completed M.TECH in Computer Science and Engineering department at National Institute of Technology, Durgapur, India in 2013. Currently she is working in IBM India Pvt. Ltd. as an Associate System Engineer.
Parag Kumar Guha Thakurta, Assistant Professor in National Institute of Technology Durgapur from India. His main research interests include mobile computing.
基于无线传感器网络的环境监测系统设计与实现
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Abstract Wireless Sensor Network, a new intelligent control and monitoring network combining sensor technology with computer and communication technology, has become a hot spot in the field of wireless communication. With the improvement of living standards, people pay more attention to environmental issues. Because of the high maintenance cost and complexity of dispose, traditional environmental monitoring system is restricted in several applications. In order to surveil the temperature and humidity of the environment, a new surveillance system based on WSN is implemented in this thesis. Sensor nodes are placed in the surveillance area casually and they construct ad hoc network automatieally. Sensor nodes send the collection data to the sink node via multi-hop routing, which is determined by a specific routing protocol. Then sink node reveives data and sends it to the remoted database server, remote users can access data through Internet. The wireless sensor network node is designed based on a wireless mcu CC2430, in which we mainly design the temperature and humidity sensors’ hardware and software as well as part of the wireless communications program. Sink node's processors is PXA270, in which we construct the sink node embedded Linux System. Port the Linux2.6 core to the platform, then implement the JFFS2 root file system. In order to facilitate debugging and data transmission, the thesis also develops the network device driver. Testing showed that each node can collect the right temperature and humidity information, and the communication is stable and good. The system is easy to deploy so the development and maintenance costs is reduced, it can be obtained data through wireless communication. It's easy to use and maintain. Key Words: Wireless Sensor Network, Environment Monitoring, Temperature and Humidity Sensor, Embedded Linux, Device Drivers
无线传感器网络路由协议
无线传感器网络的关键技术有路由协议、MAC协议、拓扑控制、定位技术等。路由协议: 数据包的传送需要通过多跳通信方式到达目的端,因此路由选择算法就是网络层设计的一个主要任务。路由协议主要负责将数据分组从源节点通过网络转发到目的节点,它主要包括两个方面的功能: 1、寻找源节点与目的节点间的优化路径。 2、将数据分组沿着优化路径正确转发。 无线传感器与传统的无线网络协议不同之处,它受到能量消耗的制约,并且只能获取到局部拓扑结构的信息,由于这两个原因,无线传感器的路由协议要能够在局部网络信息的基础上选择合适路径。传感器由于它很强的应用相关性,不同应用中的路由协议差别很大,没有通用的路由协议。无线路由器的路由协议应具备以下特点: （1）能量优先。需要考虑到节点的能量消耗以及网络能量均衡使用的问题。（2）基于局部拓扑信息。WSN为了节省通信能量,通常采用多跳的通信模式,因此节点如何在只能获取到局部拓扑信息与资源有限的情况下实现简单高效的路由机制,这就是WSN的一个基本问题。 （3）以数据为中心。传统路由协议通常以地址作为节点的标识与路由的依据,而WSN由于节点的随机分布,所关注的就是监测区域的感知数据,而不就是具体哪个节点获取的信息,要形成以数据为中心的消息转发路径。（4）应用相关。设计者需要针对每一个具体应用的需求,设计与之适应的特定路由机制。 现介绍几种常见的路由协议(平面路由协议、网络分层路由协议、地理定位辅助路由协议): 一、平面路由协议 平面路由协议中,逻辑结构时平面结构,节点间地位平等,通过局部操作与反馈信息来生成路由。当汇聚点向某些区域发送查询并等待来自于这些区域内传感器所采集的相关数据,其中的数据不能采用全局统一的ID,而就是要采用基于属性的命名机制进行描述。平面路由的优点就是结构简单、鲁棒性(即路由机制的容错能力)较好,缺点就是缺乏对通信资源的优化管理,对网络动态变化的反应速度较慢。其中典型的平面路由协议有以下几种: 1、1、洪泛式路由(Flooding): 这就是一种传统的网络通信路由协议。这种算法不要求维护网络的拓扑结构与相关路由的计算,仅要求接受到信息的节点以广播形式转发数据包。例如:S节点要传送一段数据给D节点,它需要通过网络将副本传送给它每一个邻居节点,一直到传送到节点D为止或者为该数据所设定的生存期限为零为止。优点在于:实现简单;不需要为保持网络拓扑信息与实现复杂路由发现算法消耗计算资源;适用于鲁棒性较高的场合。但同时也有相应的缺点:一个节点可能得到一个数据的多个副本;存在部分重叠,如果相邻节点同时对某件事作出反应,则两个节点的邻居节点将收到两份数据副本;盲目使用资源,无法作出自适应的路由选择。 为克服Flooding算法这些固有的缺陷,S、Hedetniemi等人提出闲聊式(Gossiping)策略。这种算法采用随机性原则,即节点发送数据时不再采用广播形式,而就是随机选取一个相邻节点转发它接收到的数据副本(避免了消息爆炸的结果)。
(中文)基于无线传感器网络桥梁安全监测系统
基于无线传感器网络的桥梁安全检测系统 摘要 根据桥梁监测无线传感器网络技术的桥梁安全监测系统，以实现方案的安全参数的需要；对整个系统的结构和工作原理的节点集、分簇和关键技术，虽然近年来在无线传感器网络中，已经证明了其潜在的提供连续结构响应数据进行定量评估结构健康，许多重要的问题，包括网络寿命可靠性和稳定性、损伤检测技术，例如拥塞控制进行了讨论。 关键词：桥梁安全监测；无线传感器网络的总体结构；关键技术 1 阻断 随着交通运输业的不断发展，桥梁安全问题受到越来越多人的关注。对于桥梁的建设与运行规律，而特设的桥梁检测的工作情况，起到一定作用，但是一座桥的信息通常是一个孤立的片面性，这是由于主观和客观因素，一些桥梁安全参数复杂多变[1]。某些问题使用传统的监测方法难以发现桥梁存在的安全风险。因此长期实时监测，预报和评估桥梁的安全局势，目前在中国乃至全世界是一个亟待解决的重要问题。 桥梁安全监测系统的设计方案，即通过长期实时桥跨的压力、变形等参数及测试，分析结构的动力特性参数和结构的评价科关键控制安全性和可靠性，以及问题的发现并及时维修，从而确保了桥的安全和长期耐久性。 近年来，桥梁安全监测技术已成为一个多学科的应用，它是在结构工程的传感器技术、计算机技术、网络通讯技术以及道路交通等基础上引入现代科技手段，已成为这一领域中科学和技术研究的重点。 无线传感器网络技术，在桥梁的安全监测系统方案的实现上，具有一定的参考价值。 无线传感器网络（WSN）是一种新兴的网络科学技术是大量的传感器节点，通过自组织无线通信，信息的相互传输，对一个具体的完成特定功能的智能功能的协调的专用网络。它是传感器技术的一个结合，通过集成的嵌入式微传感器实时监控各类计算机技术、网络和无线通信技术、布式信息处理技术、传感以及无线发送收集到的环境或各种信息监测和多跳网络传输到用户终端[2]。在军事、工业和农业，环境监测，健康，智能交通，安全，以及空间探索等领域无线传感器网络具有广泛应用前景和巨大的价值。 一个典型的无线传感器网络，通常包括传感器节点，网关和服务器，如图1
移动、联通、电信接入点设置
移动、联通、电信接入点设置 中国移动接入点设置 很多朋友在购买了新的手机后不知道如何才能顺利上网。不管您用的是Android，iOS，还是Symbian系统的手机，都需要进行简单的接入点配置。随着3G网的用户越来越多，很多人已经加入了这个新群体。但是合理的使用2G网络还是很有必要的，会为您节省不少流量。针对这一问题，笔者将详细的为您介绍各个运营商的网络接入点设置方法，让您的手机冲浪更加便捷、愉快。 首先为您介绍的是中国移动接入点的设置： 一、中国移动NET、WAP及彩信设置 （一）中国移动NET设置 Android用户依次点击手机菜单、设置、无线和网络、移动网络设置、接入点名称、新建接入点。 名称：中国移动NET设置；接入点名称：cmnet；代理：空白；端口：空白；用户名：空白；密码：空白；服务器：空白；MMSC：空白；彩信代理：空白；彩信端口：空白；彩信协议：wap 2.0；MCC：460，MNC：00,；身份验证类型：空白；接入点名称类型：default。 进入Android设置及无线和网络 （二）中国移动WAP设置 名称：中国移动WAP设置；接入点名称：cmwap；代理：10.0.0.172；端口：80；用户名：空白；密码：空白；服务器：空白；MMSC：空白；彩信代理：空白；
彩信端口：；彩信协议：wap 2.0；MCC：460，MNC：00,；身份验证类型：空白；接入点名称类型：default。 移动网络设置及接入点名称 （三）中国移动彩信设置（收发彩信用） 名称：中国移动彩信设置；接入点名称：cmwap；代理：10.0.0.172；端口：80；用户名：空白；密码：空白；服务器：空白；MMSC：https://www.wendangku.net/doc/ae2644929.html,；彩信代理：10.0.0.172；彩信端口：80；彩信协议：wap 2.0；MCC：460，MNC：00,；身份验证类型：空白；接入点名称类型：mms 。
中国移动广告词好多
竭诚为您提供优质文档/双击可除 中国移动广告词好多 篇一：史上最让人动心的十大IT广告语 史上最让人动心的十大IT广告语 1、全世界计算机联合起来，英特耐特就一定会实现 还记得中关村的那个著名的广告吗?在电子一条街的一座楼顶，悬挂着一幅巨大的广告，远一站路都能看清上面的广告词：“全世界计算机联合起来，英特耐特就一定会实现。”这个句式大部分中国人都耳熟能详，这条广告不仅能让人会心一笑，还能让人热血澎湃。 2、赢海威：中国人离信息高速公路还有多远?向北1500米。 1996年深秋的一天，北京白颐路口竖起了一面硕大的牌子，上面写着：“中国人离信息高速公路还有多远?向北1500米。”———前方向北1500米，就是瀛海威的网络科教馆。说起瀛海威，很多年轻的网民可能不知情，但是“想当年”，瀛海威曾是一面标志性的大旗，一家名声曾经如日中天的互联网先锋企业。张树新为瀛海威打出的这句广告语，其口气
之大、胆色之壮，一夜之间便令瀛海威在中关村地区迅速扬名。说不清是这句广告语成就了瀛海威，还是瀛海威成就了这句广告语，反正这句广告语已经成为很多人对早期中国互联网的一个经典记忆，说起来乐此不彼。 3、人类失去联想，世界将会怎样 联想的这个广告，不光是在IT行业，即使在整个品牌广告领域，也绝对是气势不凡的广告语。在这句广告语里，“联想”是泛义的，可以是和人类发展密切相关的“联系”、“想象”之类;而以“失去??会怎样”这样一种假设反问的形式，更加暗示受众“联想”对人类的重要性。结合前面的“联想电脑”和画面播放，这时的“联想”就成了狭义的，专指“联想”品牌。不同“联想”含义的暗合，使受众产生“联想电脑对(我们生活的)世界也是很重要的!”这种“移花接木”类型的广告词对于提升大众心目中的品牌形象比较有效。在配上那一组拥有猩猩、森林的象征着全系列沟通的电视广告也一直让人记忆深刻!联想的这个广告，比后来巨额聘请那些明星拍的广告，不知好了多少倍。 4、诺基亚：科技以人为本 来自芬兰首都赫尔辛基的一个小镇的通讯品牌诺基亚，最终能成为一个世界移动通讯巨人，这句广告语起到了很大的作用。“科技以人为本”是诺基亚的品牌核心价值。它是诺基亚在品牌传播中始终如一的理念，向消费者传递诺基亚
网络广告的互动设计论文
******************** 毕业设计（论文） 题目网络广告的互动设计 学生姓名***** 专业班级 **级*******班 学号 ******** 系别艺术系 指导教师(职称) ****** 完成时间 ****年**月** 日
网络广告的互动设计 摘要 随着科技的发展，机械智能化的普遍应用，人机互动成为当下时尚的主题，电话、短信、游戏、上网都成为生活的一部分。科学技术条件的前提给网络广告带来了独特的性质——互动性。互动普遍存在于网络以及网络广告当中，如何能够更好的运用网络广告区别于其他媒体的这一特性，这是一个至关重要的问题。 现代网络广告设计的核心在于创意，其魅力、体现水平的部分也在于创意。广告创意是个极为复杂的创造性思维活动过程，其作用是把广告设计的主题形象地表现出来。现代网络广告设计的创意最为独特之处就在于其互动性，但它并不能随兴之所至，而要遵循一定的原则性。现代网络广告设计要求“创意=创异+创艺+创益”，也就是说设计人员应该在创意和现实之间找到平衡点，不仅注重标新立异，有艺术品味，更要创造效益。 本文运用“互动”这个概念贯穿全文，论述了网络广告创意的立足根本、互动性是网络广告设计创意的关键等，最后结合自己的认识总结了互动与网络广告设计的联系。 关键词网络广告/互动性/个性化/网络
INTERACTIVE DESIGN ONLINE ADVERTISING ABSTRACT With the development of technology, the universal application of machine intelligence, human-computer interaction become the subject of the current fashion, telephone, text messaging, games, Internet access have become part of life. Scientific and technological condition of the premises to the network nature of advertising to bring a unique - interaction. Interaction exists in these networks and online advertising, how to better use of online advertising that is different from other media properties, which is a critical issue． Modern design is the core of online advertising creative, its charm also lies in part reflects the level of creativity. Advertising creative is a very complex process of creative thinking activities, its role is the subject of the advertising image to show it. Online advertising creative modern design of the most unique in its interactivity, but it can not with the claim whatever, and to follow certain principles. Design requirements of modern online advertising "creative differences + Creative = create the benefits from, "that designers should be creative and find a balance between the reality, not only focus on unconventional, artistic taste, but also to create efficiency. I n this paper, "interactive"concept throughout the text, discusses the fundamental based online advertising creative, interactive, design creativity is the key to online advertising, etc. Finally, summed up his understanding of interactive advertising with the network connection. KEY WORDS Online advertising, Interaction, Personalized,Network
基于无线传感器网络的智能交通系统的设计
一、课题研究目的 针对目前中国的交叉路口多，车流量大，交通混乱的现象研究一种控制交通信号灯的基于无线传感器的智能交通系统。 二、课题背景 随着经济的快速发展，生活方式变得更加快捷，城市的道路也逐渐变得纵横交错，快捷方便的交通在人们生活中占有及其重要的位置，而交通安全问题则是重中之重。据世界卫生组织统计，全世界每年死于道路交通事故的人数约有120 万，另有数100 万人受伤。中国拥有全世界1. 9 %的汽车，引发的交通事故占了全球的15 % ，已经成为交通事故最多发的国家。2000 年后全国每年的交通事故死亡人数约在10 万人，受伤人数约50万，其中60 %以上是行人、乘客和骑自行车者。中国每年由于汽车安全方面所受到的损失约为5180 亿(人民币)，死亡率为9 人/ 万·车，因此，有效地解决交通安全问题成为摆在人们面前一个棘手的问题。 在中国，城市的道路纵横交错，形成很多交叉口，相交道路的各种车辆和行人都要在交叉口处汇集通过。而目前的交通情况是人车混行现象严重，非机动车的数量较大，路口混乱。由于车辆和过街行人之间、车辆和车辆之间、特别是非机动车和机动车之间的干扰，不仅会阻滞交通，而且还容易发生交通事故。根据调查数据统计，我国发生在交叉口的交通事故约占道路交通事故的1/ 3，在所有交通事故类型中居首位，对交叉口交通安全影响最大的是冲突点问题，其在很大程度上是由于信号灯配时不合理(如黄灯时间太短,驾驶员来不及反应)，以及驾驶员不遵循交通信号灯，抢绿灯末或红灯头所引发交通流运行的不够稳定。随着我国经济的快速发展，私家车也越来越多，交通控制还是延续原有的定时控制，在车辆增加的基础上，这种控制弊端也越来越多的体现出来，造成了十字交叉路口的交通拥堵和秩序混乱，严重的影响了人们的出行。智能交通中的信号灯控制显示出了越来越多的重要性。国外已经率先开展了智能交通方面的研究。 美国VII系统(vehicle infrastructure integration)，利用车辆与车辆、车辆与路边装置的信息交流实现某些功能，从而提高交通的安全和效率。其功能主要有提供天气信息、路面状况、交叉口防碰撞、电子收费等。目前发展的重点主要集中在2个应用上: ①以车辆为基础; ②以路边装置为基础。欧洲主要是CVIS 系统(cooperative vehicle infrastructure system)。它有60 多个合作者，由布鲁塞尔的ERTICO 组织统筹，从2006 年2 月开始到2010年6月，工作期为4年。其目标是开发出集硬件和软件于一体的综合交流平台，这个平台能运用到车辆和路边装置提高交通管理效率，其中车辆不仅仅局限于私人小汽车，还包括公共交通和商业运输。日本主要的系统是UTMS 21 ( universal traffic management system for the 21st century , UTMS 21)。是以ITS 为基础的综合系统概念,由NPA (National Police Agency) 等5个相关部门和机构共同开发的，是继20 世纪90 年代初UTMS 系统以来的第2代交通管理系统，DSSS是UTMS21中保障安全的核心项目，用于提高车辆与过街行人的安全。因此，从国外的交通控制的发展趋势可以看出，现代的交通控制向着智能化的方向发展，大多采用计算机技术、自动化控制技术和无线传感器网络系统，使车辆行驶和道路导航实现智能化，从而缓解道路交通拥堵，减少交通事故，改善道路交通环境，节约交通能源，减轻驾驶疲劳等功能，最终实现安全、舒适、快速、经济的交通环境。
移动魔百和常见问题处理
移动通信有限公司魔百和故障处理指引中国移动通信集团公司分公司 2015年12月 目录
第1章故障总体描述 故障主要分为以下几类： 1．开通注册类，此类故障出现在用户刚开通魔百和业务时。如：手机是否欠费停机；机顶盒串号和手机号的订购关系出现问题。 2.机顶盒类，此类故障一般是软、硬件故障所致。 3.播放使用类故障，此类故障一般是用户使用不当，用户侧网络故障，或牌照方CDN 出现故障造成。
第2章故障分类 在各地市魔百和业务推广过程中，故障投诉较多，为有效指导后续售后工作，本文档对各类问题进行了归类汇总，分析原因、总结处理方法。 2.1 业务开通类 2.1.1 报错类 故障现象：“登陆失败报90056错误”、“开机认证失败”、“登陆失败”、“访问服务器失败”、“开通失败”、“网络异常” 产生问题原因： 1、机顶盒之前已经正常激活并且获取到账号密码，但是当前账号密码已经失效； 2、由于网络问题，导致首次开机没有获取到正确的账号密码。 解决方法： 1、排查网络是否正常。 2、确定机顶盒在AAA系统中无订购关系（拨打50客服查询） 3、机顶盒恢复出厂设置，重新获取一下用户名密码。 按机顶盒遥控器“设置”——“设备信息”——“启用诊断” 在第一步就会出现红色报错信息，则说明网络异常或机顶盒网络配置不正确，需先解决网络或网络配置问题； 在第二步出现开机认证失败的红色报错信息，则可以确定是开通问题，订购关系异常； 2.1.2 开机提示“机顶盒不支持互联网开通” 故障现象：开机提示“您的机顶盒不支持互联网开通，请到营业厅开通” 产生问题原因及解决方法 1、新装用户查询工单是否竣工，至少走到“施工回访”阶段。 2、机顶盒无订购关系，查询录单信息（盒子串码、手机号）录入是否有误，盒 子是否发放错误，有误则重新办理订购。 3、机顶盒恢复出厂设置，重新效验。 恢复出厂设置：按遥控器“设置”——“恢复出厂设置”——输入密码10086，点击“重置机顶盒”即自动重启，重启后需要对网络重新进行配置。
移动性浊音阳性提示腹水量
移动性浊音（shifting dullness）为临床上检查腹腔有无积液的常用方法。原理是腹腔内积聚液体较多时(约1000ml以上)，在患者取仰卧位叩诊时，液体因重力作用积聚于腹腔低处，含气的肠管漂浮其上，故叩诊腹中部呈鼓音，腹部两侧呈浊音；当患者取侧卧位时，液体积聚于下部，肠管上浮，下侧腹部转为浊音，上侧腹部则为鼓音。移动性浊音阳性说明有腹腔积液。 由于不同体位下其浊音都为阳性，那么就可以初步判断女性体内腹水比较多，一般认为移动性浊音阳性提示腹水量在1000毫升以上。因为如果少量的腹水，例如500毫升左右，是不会导致移动性浊音阳性的。移动性浊音阳性只能作为提示腹水量的一个检查，并不能判断病因，需要通过其他检查进一步判断病因 病因及常见疾病： 1.血浆胶体渗透压降低 血浆白蛋白低于25g/L或同时伴有门静脉高压，液体容易从毛细血管漏入组织间隙及腹腔，若水分漏入腹腔则形成腹水。此种情况见于重度肝功能不全、中晚期肝硬化(蛋白合成减少)、营养缺乏(蛋白摄入不足)、肾病综合征与蛋白丢失性肠病等情况。 2.钠水潴留 常见于心肾功能不全及中晚期肝硬化伴继发性醛固酮增多症。肝硬化与右心衰竭时，利钠因子活性降低使肾近曲小管对钠的重吸收增加。近年认为近曲小管的钠重吸收机制较醛固酮作用于远曲小管更为重要。
3.内分泌障碍 肝硬化或肝功能不全时，肝降解功能减退。一方面抗利尿激素与醛固酮等灭活功能降低致钠、水潴留；另一方面血液循环中一些扩血管性血管活性物质浓度增高，这些物质引起外周及内脏小动脉阻力减低，心排血量增加，内脏处于高动力循环状态。由于内脏血管扩张，内脏淤血，造成有效循环血容量相对不足及低血压，机体代偿性释放出血管紧张素II及去甲肾上腺素，以维持血压。这样因反射性地兴奋交感神经系统释放出一些缩血管物质，使肾血流量减低肾小球滤过率下降，加之抗利尿激素释放，引起肾小管钠、水回吸收增加，导致钠水潴留并形成腹水。
无线传感器网络路由协议研究【开题报告】
毕业设计开题报告 计算机科学与技术 无线传感器网络路由协议研究 一、选题的背景与意义 选题背景 随着微机电系统、无线通信技术、微型传感器技术和嵌入式技术的飞速发展，集数据采集、处理及通信功能于一体的无线传感器网络开始得到广泛的研究。网络层的路由协议是无线传感器网络研究的关键问题之一，它完成把数据分组从源节点引导到目的节点的功能。无线传感器节点是随机分布，电池供电，绝大部分的能量消耗是集中在无线通讯模块上，约占整个传感器节点能量消耗的80%。因此，目前提出的传感器节点通讯网络路由协议主要是围绕着减少能量消耗延长网络生命周期而进行设计的。 AOMDV多路径路由协议是无线传感器网络最重要的协议之一。通过它可以获得多条通信路径并且能够减少路由发现延迟，实现负载均衡，能够显著节省节点能量和防止瓶颈的产生。LEACH协议是传感器中具有负载均衡的很有用的一种协议。LEACH协议以循环的方式随机选择蔟首节点，将整个网络的能量负载平均分配到每个传感器节点中，从而达到降低网络能源消耗、提高网络整体生存时间的目的。这两种协议的研究对无线传感器路由协议的改进有很大帮助。 由于无线信道的广播特性，无线网络中任一节点发送的无线信号都可能被其通信范围的节点接收到。当局部空间范围内有两个以上的节点同时发送时，就有可能在接收节点处发生信号叠加，造成冲突，以至于接收节点无法正确接收到发送的信息。有效协调多个节点共享信道资源，避免冲突发生时无线网络面临的关键问题之一，直接影响着无线资源的使用效率、网络吞吐和时延等重要性能。所以，媒质接入控制（MAC）协议的研究也是无线传感器网络的重要课题之一。 课题意义 无线传感器网络是当前信息领域研究的热点，路由技术是无线传感器网络通信层的核心技术。目前，无线传感器网络路由协议研究的首要目标就是能量的高效利用，通过对网络层的路由协议的研究和分析，总结出优化的措施，同时基于NS2仿真平台对LEACH协议和AOMDV协议进行仿真和实验，在实验的基础上，对协议给予改进和优化，
基于无线传感网络的大型结构健康监测系统_尚盈
文章编号:1004-9037(2009)02-0254-05 基于无线传感网络的大型结构健康监测系统 尚 盈 袁慎芳 吴 键 丁建伟 李耀曾 (南京航空航天大学智能材料与结构航空科技重点实验室,南京,210016) 摘要:针对大型碳纤维复合材料机翼盒段壁板结构,实现了基于无线传感网络的多点应变结构健康监测系统,采用自组织竞争神经网络成功判别了集中载荷模拟的损伤位置。本系统由传感采集子系统、无线传感网络子系统和终端监控子系统三部分组成。为了降低系统网络功耗及成本,提高系统的稳定性和可靠性,改善传感网络的实时性和同步性,设计了可直接配接无线传感网络节点的低功耗多通道应变传感器信号调理电路和基于无线传感网络的层次路由协议,开发了多通道应变数据采集、网络簇头转发和中继节点接收等主要软件模块。实验证明,相比于传统有线的监测方法和数据采集系统,基于无线传感网络的结构健康监测系统具有负重轻、成本低、易维护和搭建移动方便等优点。 关键词:无线传感网络;结构健康监测;层次路由协议;自组织竞争网络中图分类号:T P2;T P9 文献标识码:A 基金项目:国家“八六三”高技术研究发展计划(2007AA 032117)资助项目;国家自然科学基金(60772072,50420120133)资助项目;航空基金(20060952)资助项目。 收稿日期:2007-09-05;修订日期:2008-04-17 Large -Scale Structural Health Monitoring System Based on Wireless Sensor Networks S hang Ying ,Yuan Shenf ang ,Wu J ian ,Ding J ianw ei ,L i Yaoz eng (T he A ero nautic Key La bo rat or y o f Smart M ater ial and Str uct ur e,N anjing U niv ersit y o f Aer onautics and A str onautics,N anjing,210016,China) Abstract :Aimed at the large-scale structure and anisotropy nature o f the carbon fiber compos-ite material w ing box ,a large-scale structural health m onitoring system based on w ireless sen-sor netw orks is presented .A kind of artificial neural netw ork is designed to distinguish the damag e locatio n simulated by the co ncentrated load .The sy stem co nsists o f the sensor data ac-quisition,the w ireless sensor netw or ks,and the terminal monitoring sub-sy stem s.To im pro ve the performance o f the system ,the signal conditio ning circuit and the hierarchical routing pro -to col are designed based o n w ireless sensor netw orks ,the prog rams of data acquisition and Sink node are ex ploited.Experimental result pro ves that the system has advantag es of flexibili-ty o f deplo yment,low maintenance and deploym ent costs . Key words :w ir eless senso r netw or ks ;str uctural health monitoring ;hierarchical routing ;self -org anizing com petitive netw o rk 引 言 结构健康监测技术是采用智能材料结构的新概念,利用集成在结构中的先进传感/驱动元件网络,在线实时地获取与结构健康状况相关的信息(如应力、应变、温度、振动模态、波传播特性等),结 合先进的信号信息处理方法和材料结构力学建模 方法,提取特征参数,识别结构的状态,包括损伤,并对结构的不安全因素在其早期就加以控制,以消除安全隐患或控制安全隐患的进一步发展,从而实现结构健康自诊断、自修复、保证结构的安全和降低维修费用[1]。 无线传感网络节点具有局部信号处理的功能, 第24卷第2期2009年3月数据采集与处理Jour nal of D ata A cquisition &P ro cessing Vo l.24N o.2M a r.2009
各大运营商 网络接入点设置
手机上网一点通各大运营商接入点设置 很多朋友在购买了新的手机后不知道如何才能顺利上网。不管您用的是Android，iOS，还是Symbian系统的手机，都需要进行简单的接入点配置。随着3G网的用户越来越多，很多人已经加入了这个新群体。但是合理的使用2G网络还是很有必要的，会为您节省不少流量。针对这一问题，笔者将详细的为您介绍各个运营商的网络接入点设置方法，让您的手机冲浪更加便捷、愉快。 首先为您介绍的是中国移动接入点的设置： 一、中国移动NET、WAP及彩信设置 （一）中国移动NET设置 Android用户依次点击手机菜单、设置、无线和网络、移动网络设置、接入点名称、新建接入点。 名称：中国移动NET设置；接入点名称：cmnet；代理：空白；端口：空白；用户名：空白；密码：空白；服务器：空白；MMSC：空白；彩信代理：空白；彩信端口：空白；彩信协议：wap 2.0；MCC：460，MNC：00,；身份验证类型：空白；接入点名称类型：default。 进入Android设置及无线和网络
（二）中国移动WAP设置 名称：中国移动WAP设置；接入点名称：cmwap；代理：10.0.0.172；端口：80；用户名：空白；密码：空白；服务器：空白；MMSC：空白；彩信代理：空白；彩信端口：；彩信协议：wap 2.0；MCC：460，MNC：00,；身份验证类型：空白；接入点名称类型：default。 移动网络设置及接入点名称 （三）中国移动彩信设置（收发彩信用） 名称：中国移动彩信设置；接入点名称：cmwap；代理：10.0.0.172；端口：80；用户名：空白；密码：空白；服务器：空白；MMSC：https://www.wendangku.net/doc/ae2644929.html,；彩信代理：10.0.0.172；彩信端口：80；彩信协议：wap 2.0；MCC：460，MNC：00,；身份验证类型：空白；接入点名称类型：mms 。
无线传感网路由协议的分析比较
无线传感网路由协议的分析比较 无线传感网技术是对当今经济和社会进步发挥重要作用的技术，对于现代军事、信息技术、制造业等多个重要的领域产生着巨大的影响。而无线路由协议则是无线传感网研究中的热点问题。文章对于几个典型的平面路由协议和分层路由协议进行了介绍，分析了它们各自的利弊，并对它们进行了比较。 标签：无线传感网；路由协议；传感器节点 1 无线传感网概述 无线网络即使用无线传输介质的网络。目前有两种无线网络，基础设施网络和对等网络。基础设施网络的无线终端需要配置无线网卡，并通过接入点（AP）连接入网。对等网络即Ad hoc网络，不需要AP的支持，终端设备之间可以直接通信。无线Ad hoc网络又可分为两类，移动Ad hoc网络和无线传感器网络。前者的终端是快速移动的，后者的结点是静止的或者移动很慢。 无线传感网由大量的静止或移动的传感器组成，它们以自组织和多跳的方式构成无线网络，相互协作以探测、处理和传输网络覆盖区域内感知对象的监测信息，并报告给用户。无线传感器网络技术在军事应用、智能家居、环境监测、建筑物质量监控、医疗护理等各个方面都有广泛应用[1]。 无线传感网的系统结构包括监测区域（Sensor Field）、传感器节点（Sensor Node）和汇聚节点（Sink Node）[2]。监测区域中包含了各种需要采集数据的观察对象；传感器节点用于采集观察对象的相关数据，并将处理后数据传给汇聚节点；汇聚节点用于收集由传感器节点传递来数据，并将数据传送到远程中心进行集中处理。 2 无线路由协议 无线路由协议是无线传感网研究中的热点问题。无线传感网的路由协议负责在源节点和目的节点之间可靠地传输数据，包括路由选择和数据转发两个功能。根据网络的拓扑结构是否有层次，可以将路由无线路由协议分为平面路由协议和分层路由协议[3]。 2.1 平面路由协议 平面路由协议适用于具有平面结构的网络，所有节点之间地位平等，协议相对简单。源节点和目的节点之间一般存在多条路径，可共同承担网络负荷，通常不存在瓶颈，网络具有较强的健壮性。然而，节点的组织、路由的建立、控制与维持所产生的开销需要占用较大的带宽，从而影响网络数据的传输速率。另外，当网络规模较大时需要损耗很大的能量，并且网络的可扩展性较差。因此，平面路由协议只适用于规模较小的网络。
无线传感器网络技术的应用
无线传感器网络技术的应用 摘要：无线传感器网络(WSN)是新兴的下一代传感器网络，在国防安全和国民经济各方面均有着广阔的应用前景。本文介绍了无线传感器网络的组成和特点，讨论了无线传感器网络在军事、瓦斯监测系统、智能家具，环境监测，农业。交通等方面的现有应用，最后提出无线传感器网络技术需要解决的问题。 关键词：无线传感器网络，军事、瓦斯监测系统、智能家具，环境监测，农业。交通。 1．无线传感器网络研究背景以及发展现状 随着半导体技术、通信技术、计算机技术的快速发展，90年代末，美国首先出现无线传感器网络（WSN）。1996年，美国UCLA大学的William J Kaiser教授向DARPA提交的“低能耗无线集成微型传感器”揭开了现代WSN网络的序幕。1998年，同是UCLA大学的Gregory J Pottie教授从网络研究的角度重新阐释了WSN的科学意义。在其后的10余年里，WSN网络技术得到学术界、工业界乃至政府的广泛关注，成为在国防军事、环境监测和预报、健康护理、智能家居、建筑物结构监控、复杂机械监控、城市交通、空间探索、大型车间和仓库管理以及机场、大型工业园区的安全监测等众多领域中最有竞争力的应用技术之一。美国商业周刊将WSN网络列为21世纪最有影响的技术之一，麻省理工学院(MIT)技术评论则将其列为改变世界的10大技术之一。WSN是由布置在监测区域内传感器节点以无线通信方式形成一个多跳的无线自组网（Ad hoc），其目的是协作的感知，采集
和处理网络覆盖区域中感知对象的信息，并发送给观察者。传感器、感知对象和观察者是WSN的三要素。将Ad hoc技术与传感器技术相结合，人们可以通过WSN感知客观世界，扩展现有网络功能和人类认识世界的能力。WSN技术现已经被广泛应用。图为WSN基本结构。 WSN经历了从智能传感器，无线智能传感器到无线传感器三个发展阶段，智能传感器将计算能力嵌入传感器中，使传感器节点具有数据采集和信息处理能力。而无线智能传感器又增加了无线通信能力，WSN将交换网络技术引入到智能传感器中使其具备交换信息和协调控制功能。 无线传感网络结构由传感器节点，汇聚节点，现场数据收集处理决策部分及分散用户接收装置组成，节点间能够通过自组织方式构成网络。传感器节点获得的数据沿着相邻节点逐跳进行传输，在传输过程中所得的数据可被多个节点处理，经多跳路由到协调节点，最后通过互联网或无线传输方式到达管理节点，用户可以对传感器网络进行决策管理、发出命令以及获得信息。无线传感器网络在农业中的运用是推进农业生产走向智能化、自动化的最可行的方法之一。近年来国际上十分关注WSN在军事，环境，农业生产等领域的发展，美国和欧洲相继启动了WSN研究计划，我国于1999年正式启动研究。国家自然科学基金委员会在2005年将网络传感器中基础理论在一篇我国20年预见技术调查报告中，信息领域157项技术课题中7项与传感器网络有直接关系，2006年初发布的《国家长期科学与技术发展
(完整版)网络广告创意的原则与方法
网络广告创意的原则与方法 网络广告创意是广告人员对确定的广告主题进行的整体构思活动，为了让网络广告达到达到最佳的宣传效果，根据网络媒体的特点，充分发挥想象力和创造力，提出有利于创造优秀甚至杰出广告作品的构思。创意策略以研究产品概念、目标消费者、广告信息和传播媒介为前提，是广告活动的灵魂，也是一则广告是否成功的关键。现在，网络广告的形越来越丰富，如何在网络广告设计中保持独特的创意的同时，能够很好的达到广告应有的效果是非常重要的，在网络广告创意有一些方法，也要遵循一定的原则。 网络广告的创意原则 1、目标性原则 目标性是网络广告创意的首要原则，网络广告必须与广告目标和营销目标相吻合，创意的最终目标是为了促进营销目标的实现。任何广告创意都必须考虑：广告创意要达到什麽目的?起到什麽效果？ 2、关注性原则 网络广告必须要能吸引消费者的注意力，美国广告大师大卫·奥格威说：“要吸引消费者的注意力，同时让他们来买你的产品，非要有很好的点子不可。除非你有很好的点子，不然它就像快被黑暗吞噬的船只。” 3、简洁性原则 广告创意必须简单明了，切中主题，才能使人容易读懂广告创意所传达的信息。 4、互动性原则 网络广告的创意必须关注目标对象是哪些人？他们的人文特征及心理特征是什么？从而运用网络媒体互动性的优势，设计能和受众进行互动的广告，以调动他们的兴趣，主动参与到广告活动中来。 5、多样性原则 网络广告的多样性是指网络广告表现形式多样的创意，随着WEB2.0网站的出现，广告创意应该多样化，这样才能充分利用网络的优势来达到更好的广告效果。 6、精确性原则 网络广告趋向于进行精准传输，也就是”把适合的信息传达给适合的人“。目标受众的精确定位是网络广告的创意原则之一，这是网络广告发展的未来趋势之一。 网络广告的创意方法 1、提炼主题 选择一个有吸引力的网络广告创作的主题。 2、进行有针对性地诉求 在买点的设计上，应站在访问者的角度，注意与广告内容的相关性，从而提高广告的点击率。 3、品牌就有亲和力 广告不仅是推销产品，广告同时也是建立品牌形象的一种方式，利用树立企业的品牌让用户对产品产生信心和认同。但要注意过分的品牌宣传则会降低浏览者的好奇心，降低点击率。因此，在广告创意上要注重对品牌亲和力的塑造。 4、营造浓郁的文化氛围 应用传统文化进行网络广告的创意设计，既新鲜易于受众接受，又能起到很好的效果。 5、利益诱惑 抓住消费者注重自身利益的心理特点，注重宣该传网络广告活动给浏览者带来的好处，吸引浏览者参与活动。 6、其他方法