Ultrasonic wind velocity measurement based on DSP

Ultrasonic transmitting, receiving and amplifying circuits are designed. Thereceived signals are sampled with the high speed ADC (analog-to-digital converter), and dealt withthe DSP (digital signal processing). A forward-backward IIR (infinitive impulse response) filterwith no delay is designed to filter the sampled data, and series A and B are achieved by narrow andwide band filtering, respectively. In series A, the start point of the cycle first exceeding thethreshold is calculated accuratelyby interpolation, and the start cycle is detected by fittingcycles in series A and its inversion A' to cycles in B with variance analysis. Therefore, the startpoint of the start cycle is calculated precisely. By deriving the relationships between the traveltime in the opposite directions of three axes and the airflow velocities, the wind velocity anddirection are calculated. Experiments show that the reliability and the precision are improved, andthe circuits are simplified.

Least-Square Collaborative Beamforming Linear Array for Steering Capability in Green Wireless Sensor Networks

This paper presents a collaborative beamforming （CB） technique to organize the sensor node＇s location in a linear array for green wireless sensor network （WSN） applications. In this method, only selected clusters and active CB nodes are needed each time to perform CB in WSNs. The proposed least-square linear array （LSLA） manages to select nodes to perform as a linear antenna array （LAA）, which is similar to and as outstanding as the conventional uniform linear array （ULA）. The LSLA technique is also able to solve positioning error problems that exist in the random nodes deployment. The beampattern fluctuations have been analyzed due to the random positions of sensor nodes. Performances in terms of normalized power gains are given. It is demonstrated by a simulation that the proposed technique gives similar performances to the conventional ULA and at the same time exhibits lower complexity.

Development of a New Target Simulator

The.functions of a general target simulator are too few to provide the sonar equipmentand sonar signal-Processing algorithm with a set of integrated experimental data. In this paper anew universal target simulator is developed based on the sound scattering theory. It can produceintegrated simulated data for the various existing sonar equipment and the usual sonar signalprocessing algorithms. The means and efficiency of detection of sonar equipment are improvedby this new simulator In the meantime, this new device stimulates the research on sonar signalprocessing algorithms.

An approach for automatic sleep stage scoring and apnea-hypopnea detection

In this article we present an application of data mining to the medical domain sleep research, an approach for automatic sleep stage scoring and apnea-hypopnea detec- tion. By several combined techniques （Fourier and wavelet transform, derivative dynamic time warping, and waveform recognition）, our approach extracts meaningful features （fre- quencies and special patterns like k-complexes and sleep spindles） from physiological recordings containing EEG, ECG, EOG and EMG data. Based on these pieces of in- formation, an ensemble of decision trees is constructed us- ing the principle of bagging, which classifies sleep epochs in their sleep stages according to the rules by Rechtschaf- fen and Kales and annotates occurrences of apnea-hypopnea （total or partial cessation of respiration）. After that, case- based reasoning is applied in order to improve quality. We tested and evaluated our approach on several large public databases from PhysioBank, which showed an overall accu- racy of 95.2% for sleep stage scoring and 94.5% for classify- ing minutes as apneic or non-apneic.

Optical signal processing based on silicon photonics waveguide Bragg gratings： review

This paper reviews the work done by research- ers at INRS and UBC in the field of integrated microwave photonics （IMWPs） using silicon based waveguide Bragg gratings （WBGs）. The grating design methodology is discussed in detail, including practical device fabrication considerations. On-chip implementations of various fun- darnental photonic signal processing units, including Fourier transformers, Hilbert transformers, ultrafast pulse shapers etc., are reviewed. Recent progress on WBGs- based IMWP subsystems, such as true time delay elements, phase shifters, real time frequency identification systems, is also discussed.

High-speed optical binary data pattern recognition for network security applications

All-optical high-speed binary data pattern recognition is one of the key technologies in network security applications. A serial pattern recognition scheme is presented, which can detect and locate a specified random target pattern within an input data sequence at high bit-rate. The logic operation principle is presented using logic equations. The logic AND/XNOR gates and a re- circulating loop at 10.65-42.6Gbit/s are successfully demonstrated using three semiconductor optical amplifier （SOA） based gates. The experiments have successfully demonstrated the random pattern recognition up to 256- bits at 42.6 Gbit/s.