Applied Mechanics and Materials Vols. 556-562

Abstract: Digital watermarking technology has already been used for secure data aggregation in wireless sensor networks. However, most of the existing watermarking technologies are irreversible, and the embedded watermark will cause some damage to the data collected by sensors. In this paper, we proposed a novel distributed reversible watermarking technology based on an improved difference expansion scheme. Due to the hierarchical clustering architecture organized according to LEACH protocol, a distributed self-organized mechanism is established within clusters for the watermark generation. The whole watermark is split into several segments and the watermark segments are assigned randomly to different sensors within a group. In addition, a pair of synchronized random sequence generators is applied on both the sensors and the sink to fresh the data.

Abstract: In allusion to limitations of traditional data processing technology in big data processing, big data processing system architecture based on hadoop is designed, using the characteristics of quantification, unstructured and dynamic of cloud computing.It uses HDFS be responsible for big data storage, and uses MapReduce be responsible for big data calculation and uses Hbase as unstructured data storage database, at the same time a system of storage and cloud computing security model are designed, in order to implement efficient storage, management, and retrieval of data,thus it can save construction cost, and guarantee system stability, reliability and security.

Abstract: In this paper, we investigate construction methods for producing nonbinary LDPC codes, and a family of nonbinary LDPC codes over is presented and its properties are derived. Compared to the second method presented by Ref. [5], simulation results show that the proposed LDPC codes perform well over the AWGN channel under belief propagation decoding algorithm and have an almost same BER curve as the ones in Ref. [5]. However, the resultant construction method is simpler than the latter’s.

Abstract: We study data aggregation for region-based top-k queries in wireless sensor networks, which is one kind of internet of things. Because the energy of sensor nodes is limited and a sensor node will die if it has no energy left, one of the important targets for all protocols in wireless sensor networks is to decrease the energy consumption of the sensor nodes. For a sensor node, communication cost is much more than other kinds of energy cost such as energy cost on computation and data storage. Thus, a very efficient way to decrease the energy cost of the sensor nodes is to decrease the quality of the sensing data that will be transmitted to the base station. In this paper, we use the technique of data aggregation to achieve this goal, and propose an algorithm to construct a novel Data Aggregation Tree (DAT) in the query region. To check the efficiency of DAT, we have made a simulation on OMNET, and the results show that DAT can shrink large quality of data when they are transmitted to the base station, and the life time of the sensor networks can thus be prolonged..

Abstract: In this paper we use MATLAB and VB to establish computer analysis system between the students' psychological quality and employment competition. Based on optimal solution constraint conditions and the clustering center boundary value of the student ideological quality maturity model, we establish the model of student ideological quality maturity. We introduce the numerical calculation into nearly linear equation of students' employment advantage, and obtain the advantage index of employment. This paper we use the MATLAB software to import the student ideological quality indexes, and get the students ideological quality maturity index by analysis and calculation. The maturity is displayed by GUI using VB visual. It provides a theoretical reference for the quality of the students’ ideological education.

Abstract: In this paper, we present the multi-channel transmission strategy which has primary user’s protection mechanism to improve the spectrum efficiency and study its performance under perfect and imperfect sensing. This paper also introduce IOV.IOV (Internet of Vehicle) includes the features of WSN (Wireless Sensor Networks) and VANET (Vehicular Ad Hoc Networks), is becoming the tendency in vehicular network.

Abstract: As requirements for the acquisition of workshop production information tends to be more instant and reliable, this paper proposed a workshop production information acquisition system based on RFID and ZigBee technology. After analyzing the system information demand, this paper designs the system physical structures, communication protocol, tag encoding and software hierarchy. Finally, designs and implements the server-side and terminal-side system which can make information acquisition more real-time and make the production more efficient.

Abstract: The LIFT technology has applied in process of denoising to ensure the imaging precision of minor faults and structure in 3D coalfield seismic processing. The paper focused on the denoising process in two study areas where the LIFT technology is used. The separation of signal and noise is done firstly. Then denoising would be done in the noise data. The Data of weak effective signal that is from the noise data could be blended with the original effective signal to reconstruct the denoising data, so the result which has high signal-to-noise ratio and preserved amplitude is acquired. Thus the fact shows that LIFT is an effective denoising method for 3D seismic in coalfield and could be used widely in other work area.

Abstract: To enhance the ber performance of pseudo physical-layer network coding (ppnc) scheme, a new scheme called pseudo physical-layer soft network coding (ppsnc) scheme is proposed, ppsnc adopts soft information not hard decision information, and its ber performance is better than ppnc. Meanwhile ppsnc has no synchronization problem compared with physical-layer network coding (pnc) scheme. At the same time, we also discuss the performance of ppsnc in mimo environment. The simulation results show that mimo-ppsnc outperforms the other schemes.

Abstract: The last decade has seen a significant popularity of instant messaging and its main usage is for recreational purposes. However, instant messaging can also be utilized in the workplace and by utilizing such tools more efficiency of workplace communication can be achieved. For this purpose, in this paper we conduct research on mobile instant messaging in the workplace. Mobile Internet services based communication is chosen because mobile communication is playing an important role in today's communication system. First, the system architecture of a mobile instant messaging is presented. Some main functionality, such as message exchange and file transmission, are elaborated. Then, based on this architecture, an android-based messaging client and a Linux-based server are developed. Finally, the instant messaging software is tested in a real mobile communication network and test results show that the software works well. As mobile Internet services become increasingly important, the instant messaging tool developed in this paper will be utilized in the workplace as a communication means and will improve work efficiency greatly in the future.