Applied Mechanics and Materials Vol. 740

Abstract: The energy of the nodes in wireless sensor network is very limited. Power supply module power supply, not only need to give themselves also need to collect data of the sensor power supply, monitoring data sending and receiving, processing, also need to consume energy. If the node due to run out of battery and enter a state of "death", can cause the node collection data loss; If the node is terminal nodes, only this node data loss; But if the node is routing nodes, not only can cause data loss of this node, also can cause by all nodes of the node for data transmission loss of data. So, the question of energy consumption becomes a research focus in the field. Through the architecture of wireless sensor network and the analysis of the wireless sensor network protocol stack, according to the characteristics of the wireless sensor network (WSN) and energy optimization strategy of background points out the necessity of energy optimization. By analyzing the energy consumption of wireless sensor network, the wireless sensor network energy optimization strategy is given.

Abstract: The automotive ECU, as a core component of automotive electronics, needs constant update to meet the performance requirements of the vehicle. Traditional methods, which rely on the professionals’ operations to update, cannot meet the development of vehicle network. The authors propose an automotive ECU remote update scheme in this paper. A remote download system that implements convenient and real-time automotive ECU updates is built in this paper. The system takes the mobile phone as an intermediary to communicate between the remote server and the onboard platform. Finally, the feasibility of the scheme is verified via experiments.

Abstract: In the image display and control system, a high speed dissymmetrical point to point communication port and protocol between GENIC(Gigabit Ethernet Network Interface Card) and SDRAM based on LVDS (Low Voltage Differential signaling) and STOP-WAIT ARQ protocol are designed, while the port’s speed should not below 1Gbps. Five lines LVDS signal pairs are used in one direction, including one clock and four data in the port’s electrical connections. Double-edge sampling and source synchronizing are also used. Mode 256 checkout is used to guarantee the reliable data transmission. Analysis shows that the port’s bandwidth is 1.2Gbps, the efficiency of protocol is above 99% and the protocol works steadily and reliably.

Abstract: A three-party quantum secure direct communication protocol is proposed, in which the qubit transmission forms a closed loop. In this scheme, each party implements the corresponding unitary operations according to his secret bit value over the quantum channels. Then, by performing Bell measurements on the encoded particles, each party can extract the other two parties’ secret information simultaneously. Thus the three parties realize the direct exchange successfully.

Abstract: Our project team designed and realized an Automatic Identification System (AIS) terminal equipment specifically which is based on an ARM7 chip and compatible with a self-developed FPGA chip. The main research topic is about the timeslot management and implementation in this equipment. I designed a timeslot list in the form of an array, to storage every timeslot state in each channel and current frame real-time, intuitively, and conveniently. When there is a timeslot-occupied or a timeslot-reserved in the equipment, the timeslot list can storage the timeslot state real-time. This timeslot state is defined as whether each timeslot is currently occupied, what action occupied it, how long the timeout is. And manage the timeslot every timeslot by timeout, to realize each timeslot management in A/B channels. When the equipment will select candidate timeslots to send message, it could read the timeslot state by the timeslot number directly to know whether it can send message in this timeslot. Make sure its timeslot reuse, prevent its timeslot collision, and realize the communication real-time and effective.

Abstract: In this paper, a novel approach was proposed for the topic detection which combined the multi-models. We paid attention to the content similarity, time similarity and location similarity respectively, at the same time, the Bayesian model also was researched and the atomic characteristics words were extracted. Combined the expert knowledge and multi-models, the experiment was completed and the experimental results show that the approach is effective.

Abstract: Directing against the problems of too large size of the neural network structure due to the existence of a complex relationship between the input coupling factor and too many input factors in establishing model for predicting temperature of sunlight greenhouse. This article chose the environmental factors that affect the sunlight greenhouse temperature as data sample. Through the principal component analysis of data samples, three main factors were extracted. These selected principal component values were taken as the input variables of BP neural network model. Use the Bayesian regularization algorithm to improve the BP neural network. The empirical results show that this method is utilized modify BP neural network, which can simplify network structure and smooth fitting curve, has good generalization capability.

Abstract: Formulas exist in various kinds of documents with different formats. Extracting and normalizing them into a unique form are the precondition of mathematical retrieval. In this paper, an extraction and conversion method of formulas in Word documents is built for mathematical expression retrieval. Firstly, the mathematical expressions in Word documents are detected through the processing of OLE objects. Then, the matching rules of formula format conversion are defined. Finally, the extracted mathematical expressions in OMML format are converted into LaTeX format follow the defined rules and stored in a txt file. Furthermore, the formulas exist in MathType format are stored in bitmap documents and converted into LaTeX documents through formula recognition and reconstruction module. Experiments show the effectiveness of the designed approach.

Abstract: Multiple-scale community of complex networks has attracted much attention. For the problem, previous methods can not investigate multiple-scale property of community. To address this, we propose a novel algorithm (h_LPA) to detect multiple-scale structure of community. The algorithm is a heuristic label propagation algorithm associated with spectral analysis of complex networks. Label updating strategy of h_LPA is combined with heuristic function from the perspective of networks dynamics. The heuristic function further improves the dynamic efficiency of h_LPA. Extensive tests on artificial networks and real world networks give excellent results.

Abstract: In a recent paper, Chang et al. proposed an authentication scheme for E-coupon systems and proved that their scheme can prevent a range of attacks. In this paper, we reanalyze the Chang et al.’ scheme and demonstrate that it cannot resist off-line password attack, masquerading shop attack and masquerading customer attack. Moreover, it cannot achieve two security properties that is anonymity and traceability. Meanwhile, Lee proposed an efficient chaotic maps-based authentication and key agreement scheme using smartcards for telecare medicine information systems. In the scheme, we find it also cannot resist off-line password attack, masquerading attack. Unfortunately, it resists an deadly error. So the scheme cannot run.