A clustered routing protocol based on energy and link quality in WSNs

Influenced by the environment and nodes status,the quality of link is not always stable in actual wireless sensor networks( WSNs). Poor links result in retransmissions and more energy consumption. So link quality is an important issue in the design of routing protocol which is not considered in most traditional clustered routing protocols. A based on energy and link quality's routing protocol( EQRP) is proposed to optimize the clustering mechanism which takes into account energy balance and link quality factors. EQRP takes the advantage of high quality links to increase success rate of single communication and reduce the cost of communication. Simulation shows that,compared with traditional clustered protocol,EQRP can perform 40% better,in terms of life cycle of the whole network.

The Design of Wireless Sensor Network System based on ZigBee Technology

The paper design hardware platform based on network node, and analyze ZigBee protocol architecture and standards of each layer; on based of ZigBee protocol stack, we design the application program of network coordinator and terminal node to realize the data acquisition; design of network system has the characteristics of low cost, small volume, test results show that the mesh topology, network support, can be rapidly deployed, temperature, humidity, light intensity information of the smooth reading environment, that can be used for domestic environmental monitoring field.

Ant-Colony Based Routing Algorithm in Wireless Sensor Networks

In the wireless sensor networks, high efficient data routing for the limited energy resource networks is an important issue. By introducing Antcolony algorithm, this paper proposes the wireless sensor network routing algorithm based on LEACH. During the construction of sensor network clusters, to avoid the node premature death because of the energy consumption, only the nodes whose residual energy is higher than the average energy can be chosen as the cluster heads. The method of repeated division is used to divide the clusters in sensor networks so that the numbers of the nodes in each cluster are balanced. The basic thought of ant-colony algorithm is adopted to realize the data routing between the cluster heads and sink nodes, and the maintenance of routing. The analysis and simulation showed that the proposed routing protocol not only can reduce the energy consumption, balance the energy consumption between nodes, but also prolong the network lifetime.

Research on fast real-time adaptive audio mixing in multimedia conference

In multimedia conference, the capability of audio processing is basic and requires more for real-time criteria. In this article, we categorize and analyze the schemes, and provide several multipoint speech audio mixing schemes using weighted algorithm, which meet the demand of practical needs for real-time multipoint speech mixing, for which the ASW and AEW schemes are especially recommended. Applying the adaptive algorithms, the high-performance schemes we provide do not use the saturation operation widely used in multimedia processing. Therefore, no additional noise will be added to the output. The above adaptive algorithms have relatively low computational complexity and good hearing perceptibility. The schemes are designed for parallel processing, and can be easily implemented with hardware, such as DSPs, and widely applied in multimedia conference systems.

Secure planar convex hull protocol for large-scaled point sets in semi-honest model

Efficiency and scalability are still the bottleneck for secure multi-party computation geometry （SMCG）. In this work a secure planar convex hull （SPCH） protocol for large-scaled point sets in semi-honest model has been proposed efficiently to solve the above problems. Firstly, a novel priva- cy-preserving point-inclusion （PPPI） protocol is designed based on the classic homomorphic encryp- tion and secure cross product protocol, and it is demonstrated that the complexity of PPPI protocol is independent of the vertex size of the input convex hull. And then on the basis of the novel PPPI pro- tocol, an effective SPCH protocol is presented. Analysis shows that this SPCH protocol has a good performance for large-scaled point sets compared with previous solutions. Moreover, analysis finds that the complexity of our SPCH protocol relies on the size of the points on the outermost layer of the input point sets only.

A Secure and Pragmatic Routing Protocol for Mobile Ad hoc Networks

An ad hoc network is a group of wireless mobile computers(or nodes),in which individual nodes cooperate by forwarding packets for each other to allow nodes to communicate beyond direct wireless transmission range.Because of node mobility and power limitations,the network topology changes frequently.Routing protocol plays an important role in the ad hoc network.A recent trend in ad hoc network routing is the reactive on-demand philosophy where routes are established only when required.As an optimization for the current Dynamic Source Routing Protocol,a secure and pragmatic routes selection scheme based on Reputation Systems was proposed.We design the Secure and Pragmatic Routing protocol and implement simulation models using GloMoSim.Simulation results show that the Secure and Pragmatic Routing protocol provides better experimental results on packet delivery ratio,power consumption and system throughput than Dynamic Source Routing Protocol.

On-demand multicast routing protocol based on node classification in MANET

An improved on-demand multicast routing protocol(ODMRP), node classification on-demand multicast routing protocol(NC-ODMRP), which is based on node classification in mobile ad hoc networks was proposed. NC-ODMRP classifies nodes into such three categories as ordinary node, forwarding group(FG) node, neighbor node of FG node according to their history forwarding information. The categories are distinguished with different weights by a weight table in the nodes. NC-ODMRP chooses the node with the highest weight as an FG node during the setup of forwarding group, which reduces a lot of redundant FG nodes by sharing more FG nodes between different sender and receiver pairs. The simulation results show that NC-ODMRP can reduce more than 20% FG number of ODMRP, thus enhances nearly 14% data forwarding efficiency and 12% energy consumption efficiency when the number of multicast senders is more than 5.

Potential field based hole detour routing algorithm in wireless sensor networks

The current geographic routing protocols arise data congestion if a multi-flow bypasses a hole simultaneously and excessive energy consumption of hole boundary nodes because these protocols tend to route data packets along the boundaries of void areas （holes） by perimeter routing scheme.This scheme possibly enlarges the holes phenomenon （called hole diffusion problem） and shortens the life span of the network. A novel geographical routing algorithm based on a potential field approach （PFA） is proposed to deal with multiple holes scenario and restrict data to forward near boundary of a hole. That is, data packets are attracted to its sink and are repulsed away from the hole （s）. Simulation results show that PFA is superior to other protocols in terms of packet delivery ratio, network lifetime.

Research on the Application of Infrared Communication based on the embedded System and IOT

From the view of practical application, this paper designs an infrared information collection nodes, the coordinator node, wireless transmission system using CC2430 microcontroller, and in detail design the infrared sensor （temperature, heart rate, ECG / pulse） circuit diagram. This paper set up a wireless network （ZigBee protocol）, sensor signal acquisition, wireless transmitting and receiving, serial communication software design of coordinator node and PC machine. Finally, we on-line debug each module of the system hardware and software. Experiments show that the network node data transmission accurate, reliable work, has basically met the design requirements.

Design and Implementation of Remote Health Monitoring Sensor Network Based on the Internet of Things

From the view of practical application, this paper designs the human body physiology information collection nodes, the coordinator node, wireless transmission system using CC2430 microcontroller, and detailed design information of human body sensor （temperature, heart rate, ECG / pulse） circuit diagram. This paper set up software of a wireless network （ZigBee protocol）, sensor signal acquisition, wireless transmitting and receiving, and communicate with PC machine by serial communication coordinator node. Experiments show that the network node data transmission accurate, reliable work, basically reached the requirements of the design issues.

G-MER： Green Mobility Estimation- Based Routing Protocol in Wireless Sensor Network

As a core technology of Intemet of Things （loT）, Wireless Sensor Network （WSN） has become a research hotspot recently. More and more WSNs are being deployed in highly mobile environments. The fast moving sensor nodes bring significant challenges for the routing decision. In this paper, we propose an efficient logical location method, and designe a mobility estimating metric and derive a novel Green Mobility Estirmtion- based Routing protocol （G-MER） for WSNs. We also set up a full framework to evaluate its per- formance. Simulation results illustrate that G-MER achieves a fairly better perforrmnce in terrm of broadcast times and link failures than AODV. What＇s more, it decreases the mean hops by about 0.25 and reduces energy consumption by about 10% during the whole experiment. All the results show that G-MER can be effectively used in fast- moving and limited resource scenarios.

Design and implementation of ethernet passive electronic network over coax

To increase the limit of ethernet over coax （EoC） technology in the bidirectional reform of the hybrid fiber coaxial （HFC） network, an ethernet passive electronic network （EPEN） system based on Coax is proposed and experimentally demonstrated in this paper. The proposed EPEN exploits the existing capabilities of the MAC layer in the ethernet passive optical network （EPON） for reduction of cost of the HFC network. As the MPCP （multi-point control protocol） is introduced in the EPEN, bandwidth control and higher efficiency can be achieved. The experimental results exhibit the throughput of system up to 100Mbps, which meet the requirements of HFC network. To improve the performance of EPEN, frequency division multiplexing （FDM） can be used for further increase of the throughput and more hardware processing modules in the future. can be implemented to enhance the capacity

A study of venue marketing mix for MICE industry in Thailand

The objectives of the research are to determine the important factors and the performance factors of the attributes in selecting venues （particularly convention hotels and convention centers） through investigating the meeting planners＇ set of needs and to identify factors and attributes relating to the venue marketing mix for MICE industry in Thailand. This paper has applied the hospitality and the tourism marketing mixes that are important to the MICE destination selection （particularly venues） for creating a new venue marketing mix. Therefore, the study is based on the importance levels of venue selection through each marketing mix factors including all attributes in the meeting planners＇ perspectives on behalf of their organizations, which will be able to reflect a set of their real needs that could bring about development of a venue marketing mix model that exclusively accommodates MICE organizers. The data was collected using self-administered questionnaires from 229 meeting planners. Statistically significant determinants of the meeting planners＇ overall importance levels indicated that in all of the 8 marketing mix factors （68 attributes）, the people factor was perceived to be the most important factor. The package factor was perceived to have a moderate level of importance. The other factors perceived to be important included Product, Price, Place, Promotion, Physical evidence and Process. It is also found from the factor analysis that the new venue marketing mix contained 8 marketing mix factors with 61 attributes for venue business in Thailand. It is recommended from the research findings that venue management be more concerned with and focus on the attributes of the people factor.

Cooperative Layer-2 Based Routing Approach for Hybrid Wireless Mesh Networks

In a Wireless Mesh Network(WMN),the convenience of a routing strategy strongly depends on the mobility of the intermediate nodes that compose the paths.Taking this behaviour into account,this paper presents a routing scheme that works differently accordingly to the node mobility.In this sense,a proactive routing scheme is restricted to the backbone to promote the use of stable routes.Conversely,the reactive protocol is used for searching routes to or from a mobile destination.Both approaches are simultaneously implemented in the mesh nodes so that the routing protocols share routing information that optimises the network performance.Aimed at guaranteeing the IP compatibility,the combination of the two protocols in the core routers is carried out in the Medium Access Control(MAC)layer.In contrast to the operation in the IP layer where two routing protocols cannot work concurrently,the transfer of the routing tasks to the MAC layer enables the use of multiple independent forwarding tables.Simulation results show the advantage of the proposal in terms of packet losses and data delay.

Improved Consensus Speed for Discrete-Time Multi-agent Systems

The consensus problem of a linear discrete-time multi- agent system with directed communication topologies was investigated. A protocol was designed to solve consensus with an improved convergence speed achieved by designing protocol gains. The clo6ed-loop multi.agent system converged to an expected type of consensus function, which was divided into four types： zero, non- zero constant vector, bounded trajectories, and ramp trajectories. An algorithm was further provided to construct the protocol gains, which were determined in terms of a classical pole placement algorithm and a modified algebraic Riccati equation. Finally, an example to illustrate the effectiveness of theoretical results was presented.

A FUNCTION NODE-BASED MULTIPLE PAIRWISE KEYS MANAGEMENT PROTOCOL FOR WIRELESS SENSOR NETWORKS AND ENERGY CONSUMPTION ANALYSIS

In this letter, a Function node-based Multiple Pairwise Keys Management (MPKMF) protocol for Wireless Sensor Networks (WSNs) is firstly designed, in which ordinary nodes and cluster head nodes are responsible for data collection and transmission, and function nodes are responsible for key management. There are more than one function nodes in the cluster consulting the key generation and other security decision-making. The function nodes are the second-class security center because of the characteristics of the distributed WSNs. Secondly, It is also described that the formation of function nodes and cluster heads under the control of the former, and five kinds of keys, i.e., individual key, pairwise keys, cluster key, management key, and group key. Finally, performance analysis and experiments show that, the protocol is superior in communication and energy consumption. The delay of establishing the cluster key meets the requirements, and a multiple pairwise key which adopts the coordinated security authentication scheme is provided.

A utility-optimal backoff algorithm for wireless sensor networks

A novel backoff algorithm in CSMA/CA-based medium access control (MAC) protocols for clustered sensor networks was proposed. The algorithm requires that all sensor nodes have the same value of contention window (CW) in a cluster, which is revealed by formulating resource allocation as a network utility maximization problem. Then, by maximizing the total network utility with constrains of minimizing collision probability, the optimal value of CW (Wopt) can be computed according to the number of sensor nodes. The new backoff algorithm uses the common optimal value Wopt and leads to fewer collisions than binary exponential backoff algorithm. The simulation results show that the proposed algorithm outperforms standard 802.11 DCF and S-MAC in average collision times, packet delay, total energy consumption, and system throughput.

“后茶馆式”教学,构建学生主体性课堂

新改革要求课堂教学要凸显学生的主体性。运用'后茶馆式'教学的初中历史课堂教学如何凸显学生的主体性,我试从'后茶馆式'教学关注的学生在'学'的过程中暴露的'难点'、凸显的'议点'和找到的'通点'这三方面并结合案例来探讨,以期构建学生主体性课堂。

A PROBABILISTIC CHARACTERIZATION OF A FAULT-TOLERANT GOSSIPING ALGORITHM

Gossiping is a popular technique for probabilistic reliable multicast （or broadcast）. However, it is often difficult to understand the behavior of gossiping algorithms in an analytic fashion. Indeed, existing analyses of gossip algorithms are either based on simulation or based on ideas borrowed from epidemic models while inheriting some features that do not seem to be appropriate for the setting of gossiping. On one hand, in epidemic spreading, an infected node typically intends to spread the infection an unbounded number of times （or rounds）; whereas in gossiping, an infected node （i.e., a node having received the message in question） may prefer to gossip the message a bounded number of times. On the other hand, the often assumed homogeneity in epidemic spreading models （especially that every node has equal contact to everyone else in the population） has been silently inherited in the gossiping literature, meaning that an expensive mcnlbership protocol is often needed for maintaining nodes＇ views. Motivated by these observations, the authors present a characterization of a popular class of fault-tolerant gossip schemes （known as ＂push-based gossiping＂） based on a novel probabilistic model, while taking the afore-mentioned factors into consideration.

Determinants of lexical access in pure-anomic recovery:a longitudinal study

Many studies involving lexical access in picture-naming tasks have been undertaken at a point in time,mainly focusing on age of acquisition(AoA).To identify the real determinates of lexical access in recovery and their traces in the brain,we carried out a longitudinal study on a Chinese pure anomic patient using multiple logistic regression analysis.We found that AoA played an important role in early recovery but not in total recovery,whereas familiarity was significant in the whole process.From a new dynamic point of view,our results indicate that AoA and familiarity are the main determinants of lexical access in anomia recovery.We suggest that the changing effects of AoA during recovery may be related to the pathologic process;AoA and familiarity should be taken into account in constructing materials to assess and treat anomic patients.