Parallel service is mostly adopted in servers to respond to clients’ requests,but this service type is at expense of system cost and in lack of sufficient resources.Thread pool turns out to be a good alternative to tackle the problems mentioned.In this paper,based on the analysis of POSIX thread library,an embedded-thread-pool system(ARM9) with ARM9 as the hardware platform is proposed.In addition,optimization is applied in solving several main problems found in thread pool design.
A novel mixing speech retrieval algorithm was presented.The characteristics of BBS(blind source separation) of ICA(independent component analysis) was used.The mixing speech records which contained a couple of different person's voice were separated into single speech records which contained only one person's voice.New speech database based on single speech records was established.The linkage between new speech database and original speech database which contained mixinged speech records was established.In query phrase,DTW(dynamic time warping) algorithm was used for retrieval matching and the function of retrieval based on mixing speech was achieved.Experimental result shows that algorithm of this paper can find demand records in mixing speech records.
Through analyzing the melody and expression,a music retrieval system is proposed and implemented based on the selected melody features.The system supports two kinds of enquiry simultaneously,i.e.,manual input and singing input.The proposed system has high recognition rate and is pratical for small-scale database applications.
Trusted computing technology is one of research hotspots of the computer security. Adopting of trusted computing technology can greatly enhance the reliability of terminals and network communication. In order to use trusted computing technology in video surveillance system, a scheme of video surveillance server embedded TPM is designed in this paper. The security of video surveillance server is improved to use the function of TPM about encryption engine, storage protection and thought of trusted computing. This technology based on hardware is more efficient than the security technology based on software.
A multi-path video surveillance system based on embedded Linux is presented in this paper.The core of system is ARM micro processor and embedded Linux.Supported by Internet,the system is introduced in both hardware and software perspectives.A USB camera and an embedded chip with WebServer are applied in the presented system,and the purpose of server surveillance is attained through the means of imbedding WebServer.
Audio watermarking that modulates DC level shift according to watermark has wonderful low pass and noise resistance performance.When loss of watermarking synchronization occurs,if the shift of synchronization position is trivial,the sign of DC level will not be changed,but if notable,the sign of DC level will be changed,as result watermarking extracting error occurs.In order to resist de-synchronization attacks,an improved algorithm that embeds training sequence in cover audio is proposed.Experimental results show that this technique obviously improves the watermarking robustness resistance to de-synchronization attacks.
An audio watermarking algorithm based on mean quantization in the wavelet domain is presented.To reduce the effect of attacks on embedded watermark,mean quantization technique is used to embed the watermark.In this algorithm,the audio signal is decomposed using appropriate wavelet basis.Low frequency coefficients are selected to embed watermark using mean quantization method.The watermark can be extracted without the original digital audio signal.Experimental results show that compared with basic quantization watermarking algorithm,the algorithm presented in this paper is robust to many attacks,such as MP3 compression,requantization,resampling,low pass filtering,and noise addition and so on,and the robust performance has been improved highly.
