Journal of China Universities of Posts and Telecommunications最新文献

Business process families provide a unified representation of the possible business processes of a specific domain for rapid developments. The configuration of business process families depends on a group of stakeholders' requirements. However, multi-stakeholders' quality requirements and their priorities have been frequently neglected during business process configurations. In this paper, we introduce the collaborative configuration process and define the fuzzy multi-stakeholder evaluation model. Then fuzzy multi-objective collaborative evaluation method is presented to balance stakeholders' quality requirements and their preferences. The fuzzy collaborative evaluation method is divided into two stages, which consider both the important degree of each stakeholder and the weight of each objective. At last, an application is demonstrated to show the feasibility of the method.

With the aid of vector network analyzer (VNA), a relatively simple polarization scattering matrix (PSM) measurement system is constructed in an anechoic chamber. Four antennas with different polarization are connected for dual-channel measurement, then the PSM parameters and the frequency-amplitude characteristic can be obtained, finally the calibration is completed with three known model, with the help of metal disc, a vertical dihedral and a dihedral rotated at 22.5°, a polarization scattering matrix of a ball is measured in the experiment, The results show that polarization purity of the system reaches 25 dB without calibration, and can be better than 40 dB after that. Moreover, the system is easy to achieve.

In the application of mobile network and internet of things (IOT), users often set sensitive information to avoid the privacy disclosing. But sometimes users are not sure whether or not to set the sensitive information open or which item should be set open. An automatically privacy setting algorithm based on Rasch model with new parameters is proposed to solve the privacy settings automatically. The proposed algorithm statistically analyses the collected users' settings information and get the summary of each user's privacy rate and privacy settings. So, new users with their privacy concern levels can find the closest privacy rate and their best privacy settings in the summary table.

In order to overcome imperfections in manufacturing process, mechanical stress or temperature which can cause birefringence with difference in the phase and group velocities of the two orthogonal polarized modes, a new adaptive polarization mode dispersion (PMD) compensation method in 80 Gbit/s optical communication is proposed. In the experiment of this paper, through the control of digital signal processor (DSP), the dithering particle swarm optimization (PSO) algorithm is used to extract the best degree of polarization (DOP), the DOP is utilized to compensate three stage PMD of optical fiber. The experiment results show that the high speed polarization monitoring unit seriously decreases the polarization monitoring time for adaptive PMD compensation and makes the PMD compensation system work effectively.

Reduce backup window with lower system overheads is a challenge for backup system in massive small files environment. In this article, a new autoregressive-based online backup scheme for small files (ABBSF) is presented to achieve the goal by enhancing the utilization ratio of bandwidth resource in normal times. ABBSF exploits single transfer pattern and package transfer pattern to deal with small files. ABBSF employs single transfer to send one small file to the backup side periodically, and collects the network situation in this procedure. According to these network performance information, it builds autoregressive-based model for predicting available network bandwidth in the next period. Meanwhile, it provides predictive step length control to make more utilization of predictive model for maintaining low system overheads. On the basis of prediction, ABBSF makes appropriate transfer policy for package transfer. Finally, it employs package transfer to pack several files and sent them to the backup side. Experiments show that ABBSF has a good performance of prediction with relatively low system overheads to make full use of network bandwidth when backup small files.

Physical layer network coding (PNC) exploits the broadcast nature of wireless channels to obtain transmission efficiency gains over traditional network coding schemes. Nevertheless, most PNC schemes are proposed for the two-way relay network where a terminal node is not only a source but also a destination. This paper proposes a joint network coding and modulation (JNCM) scheme under a more general one-way relay network. The JNCM scheme is operated over hybrid field. It is able to adjust its transmission rate according to the channel condition, and enables a reliable transmission of different throughput under different signal-to-noise ratio (SNR). The proposed scheme achieves a better transmission efficiency than the PNC scheme based on the structure codes and a better symbol error rate (SER) performance than the complex field network coding. The excellent performances of JNCM are proved by our simulation results.

The purpose of this project is to implement the fractional Fourier transform (FrFT) on chirp signals and realize the detection and parameter estimation of different chirp signals. In the application of FrFT, pre-estimated method is proposed in this paper to improve the speed of peak searching in the parameter estimation, and suitable dimensional normalization method is selected. So that, a faster and more effective pre-estimation searching method is proposed, and the parameters such as the frequency modulation slope, center frequency, and amplitude can be estimated at the same time. From the simulation results, the estimation of parameters for multi-components chirp signals can be actualized based on FrFt, and the mixed signals can be identified successfully.

Since IPv4 address space is already depleted and many IPv6 trial networks have been verified successfully, it is urgent to deploy IPv6 commercial networks in large scale. Most Internet applications or services are still based on IPv4 protocol only. The intercommunication between IPv6 hosts and IPv4 services is needed. Besides, even if IPv6 backbones are built up overnight, there will be many IPv4 islands isolated by IPv6 oceans. IPv4 hosts will have great difficulty to access IPv4 contents in Internet data centers (IDC) when scheduled by the global server load balancer of content delivery network (CDN). This paper proposes a new IDC IPv4/IPv6 transition solution to solve these problems. It has been deployed in IPv6 campus network and provides IPv6 users with IPv4 contents from CDN based on IPv4.

This paper firstly analyzes the background of the Internet of things (IoT) and describes the trusted computing technologies concept about trusted cryptography modules (TCM), then describes its basic hierarchy and gives a basic security model based on a simple IoT system. And based on this security model, a secure solution of trusted IoT has been built by using the TCM-based technology, and it covers secure boot, secure storage, platform metrics and trusted reports, key functions, and then gives the protocol design with these functions. After analysis results, the solution can provide safeguard of security and trustworthy for their development and application.

This paper proposes an invertible entanglement matching method to realize an optimal probabilitic teleportation by introducing an auxiliary quantum channel. This requires the channel parameter matrix (CPM) of the auxiliary quantum channel to be equal to the invertible matrix of CPM of the transmission channel. By using this method, the probability of successful teleportation is more than 1/2.