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In order to alleviate the problem of data sparsity and cold start, and improve the prediction accuracy, in this paper, we combine the user’s social network and scoring records, based on the existing work, based on the existing Bayesian probabilistic matrix factorization model, a Bayesian improved social matrix factorization algorithm based on probabilistic matrix factorization model is proposed. The experimental results show that the prediction accuracy of our method is higher than the existing methods.

Terahertz absorption spectra of four DNA nucleobases were studied by terahertz time domain spectroscopy and Fourier transform infrared spectroscopy and demonstrated by calculating corresponding vibration modes using the extended generalized energy-based fragmentation approach under periodic boundary conditions method (PBC-GEBF). The experimental results were demonstrated to be in good agreement with the calculated values. We also investigated the absorption spectra of unit cell of the nucleobase crystals to clarify that all the vibrational modes belong to collective vibrational modes, which include intermolecular and intramolecular vibration and rotation, in the frequency range of 0.5–9 THz.

We propose a novel training symbol structure for polarization division multiplexed (PDM) coherent optical orthogonal frequency division multiplexing (CO-OFDM) system. We deduce the mathematical model for the scheme. Based on the given model, a novel compensation method is introduced to compensate the IQ imbalance. The theoretical analysis is validated by numerical simulation, in which we apply the Quadrature Phase Shift Keying (QPSK) modulation at a data rate of 75.211Gb/s over 50 km and data rate of 100Gb/s over 320 km transmission. Compared with the commonly used approach, the proposed scheme demonstrates better system BER performance against IQ imbalance.

The deployment of Web services based SOA applications on the Internet has led to a massive increase in the number of services. However, in these circumstances, how to select and composite proper services to meet users' complex business demands becomes a serious challenge. One of the problems lies in the benefit conflicts between the Service Requesters (SRs) and the Service Providers (SPs) in service selection. To combat this, a novel benefit equilibrium driven service selection approach is proposed. Based on the game theory, this paper puts forward a utility evaluation method for both SRs and SPs. Then a corresponding mathematical model for benefit equilibrium driven services selection is designed. Finally an Adaptive Genetic Algorithm (AGA) is used to search an appropriate composite service. Simulation results have shown that the proposed method helps to improve the synthetic utility of SRs and SPs.

In service-oriented application, individual Web services usually cannot satisfy customers' requirements, therefore, existing services always need to be integrated to create new value added composed services. To address this concern, a novel Particle Swarm Optimization (PSO) based service selection method is proposed to select appropriate services to construct a composite service which can meet the overall QoS (Quality of Service) requirements of customers. The proposed method adjusts the boundary of the search space adaptively to make the space extend or constrict with the movement of particles. Simulation results have shown that the proposed method is both feasible and effective.

In this paper, the vehicle cycle environment impacts of a mid-size passenger car in China is performed, with a special focus on the primary energy consumption and greenhouse gas (GHG) emissions. The vehicle cycle analysis results show that the energy consumption and GHG emissions of a passenger car in China are about 91.1 GJ and 11.5 ton per vehicle, respectively. And coal as the main process fuel in China is the key contributor to the high GHG emissions. The material production process is very energy-intensive, and vehicle assembly process is very emission-intensive. The energy consumption and GHG emissions of the remaining stages are small compared to the overall vehicle cycle impacts. There are three means to reduce vehicle cycle environmental impacts: automotive light weighting, adopt low energy-intensive and low emission-intensive materials in vehicle, and substitute environment friendly energy for coal as the main process fuel in China.

In order to make full use of texture features of image when fusing images, and taking into account the inherent advantages of fractal theory in this respect, a novel image fusion algorithm, which used fractal dimension and directional contrast, based on multi-wavelet transform was proposed in this paper. This fusion algorithm decomposed original images needed to be fused by multi-wavelet transform firstly, then fractal dimensions of the corresponding decomposing low-frequency coefficients were calculated by Differential Box Counting method, and the low frequency fusion rule based on fractal dimension was set up. The high frequency parts were fused by selecting method or weighted averaging method according to the directional contrast values. The fusing experiment using this algorithm to IR image and visible light image was done. In order to illustrate the performance of the algorithm, particularly the impact of introduction of fractal theory on the fusion performance, the result of those fusion algorithms that only uses multi-wavelets transform were given as well. Moreover, the objective indexes, which are image entropy, standard deviation and quality measure, were adopted to evaluate the comparative results of evaluating fusion quality. The results show that the leading of fractal dimension into image fusion processing is effective, and it performs obviously better in increasing the amount of information, the standard deviation and the quality of fused image.

This paper explains the important location and role of high-frequency electronic circuits course in all specialized courses. The specific teaching objectives and the main teaching contents of high-frequency electronic circuits are introduced. In view of characteristics of high-frequency electronic circuits, multiple scientific methods of teaching are proposed by the authors. The multiple methods include heuristic method of teaching, inductive and summative method of teaching, comparative method of teaching, and making full use of multimedia courseware and simulation software, and so on.

A fiber Bragg grating (FBG) sensor was fixed on the uniform strength beam with screws and modified acrylate. The influence of fixing method on FBG strain sensor was investigated experimentally. The wavelength shifts of the FBG sensor fixed by screws and modified acrylate were measured with different strains in the temperature range 0°C-40°C. The linearity, sensitivity and their stability at different temperature of FBG sensor which fixed with different methods were analyzed. The results show that, the FBG sensor fixed with the modified acrylate has a high linearity and a higher sensitivity which is 2.04 pm/μe. Its linearity and sensitivity have a high stability at different temperatures. The FBG sensor fixed with screws has a high linearity and a lower sensitivity which is 1.47 pm/μe. Its linearity and the sensitivity only have slight variation at different temperatures.

In this paper, a simulation model was built for in- cylinder stratified charged and lean combustion GDI engine, and the spray model was validated. Based on this, numerical simulation of mixture stratified combustion was performed in a gasoline direct injection (GDI) engine with AVL FIRE. The effects of different injection timings on the mixture quality near the spark plug were analyzed and the results showed that injection timings would significantly influence the fuel stratification pattern and the combustion characteristics. Improper injection timings would make the mixture too lean or too rich near the spark plug, resulting in a poor combustion. For a GDI engine, injection timing will play an important role in the success of stratified combustion.

Service Composition becomes the most interesting challenges in the Web services area. In this paper, the Quality of Service (QoS)-aware composition of Web Services is discussed. In this paper, we describe the web services composition process model with a directed graph, and simplexes the model by converting all connections into sequence ones. At last, an adaptive genetic algorithm is prompted to gain the solution. Experiment results show that this model is feasible and effective.

Impact of the channel estimation error and feedback delay on the throughput of multi-input and multi-output (MIMO) downlink systems is investigated. The dynamic transmission schemes based on TDMA and SDMA with zero-forcing beamforming (ZFBF) are described and their associated system throughput are compared. It is shown that the system performance is sensitive to the channel estimation error, and degrades significantly as variance of estimation error increases.

It is researched that the porting of the embedded real-time operating system μC/OS- Ⅱ to the DSP based system and the bootloader. The difficulties of porting and bootloader are resolved, and the porting system is scaled. The porting and the bootloader have been implemented on a data acquisition minimum system based on TMS320VC5416. The system runs stably, and meets with the design requirements.

The implementation of the pipe line leakage detecting system based on DSP is introduced in this paper. Because the acoustic signal is very weak that is transmitted from the pipe line leakage, it is the key issue to design the pipe line leakage detecting equipment that how to restrain the influence of the environment noise ,especially the strong signal of 50Hz electric power net. In this paper, the low noise chip is used to design the charge amplifier and two stages 50Hz notch filter which restrains the input disturbance signal to DSP effectively, and increases the SNR greatly. And an 8 channels software band-pass filter is implemented. That filters the noise out band of the leakage frequency. From the field testing result, the system has great effective to the detecting of the pipe line leakage if the environment noise is not larger than 40db.

Design of system for wireless commutation and data acquisition and transplant method of embedded real-time operating system on DSP are mainly researched. The difficulties of transplant and multi-task acquisition and communication of synchronous signal are resolved. And after transplant, the system is scaled. The transplant and boot loader are both burned on the system board for wireless commutation and data acquisition that based on TMS320VC5416 DSP. The system runs stably and the indicators meet the design requirements.

A real-time signal acquisition system based on MS320VC5416 DSP is designed for the functional requirements of portable underground pipe water leakage detector. Realization of the IIR digital filter algorithm based on DSP is proposed, at the same time, the key technologies of filter order, filter algorithm, sample frequency, clock frequency are also analyzed. Testing on-the-field and simulation analysis show that real-time, stability and antinoise capabilities of the system meet the design requirements.

According to the functional requirement of the portable underground pipe water leakage detector, a real-time signal acquisition and transporting system based on MS320VC5416 DSP is designed. The realization of the FIR digital filter algorithm on DSP is proposed and the key technologies of filter order、filter algorithm、sample frequency 、clock frequency are analyzed. Testing on-the-spot and simulation analysis show that the real-time, stability and antinoise capabilities of the system meet with the design requirements.

This paper examines IT engineering education and attempts to highlight the need for Quality Management and Assurance Systems such as the ABET international quality standard system. This will be achieved by focusing on the education practice of the Neusoft Institute of Information (Neusoft II), an institution that has committed in its charter to continuous improvement of personnel training and the creation of a first class IT Application-Oriented University.

The Knowledge Management System for domestic appliance repair is a practical working support system. The main framework comprises three tiers: ASP platform, knowledge server and knowledge management terminal. According to the demands of repair knowledge and the types of knowledge, the system provides communication platforms for repairers and online document search of technology information about domestic appliances. The main contribution is that it establishes a case base of repair experiences to manage the tacit knowledge by case-based reasoning. The system is very useful in practice.

Workflow technology is directly objected to the application of industry and business. Distributed control system (DCS) is the combination of computer technology, communication technology, CRT technology and control technology. In this paper, we will introduce the design and implementation of a workflow based distributed control system on PC network, SCS-Smart Control System, which can provide several useful functionalities.