Egg quantity determination based on characteristic polarisation state
Due to the disability of the traditional complex natural resonant method, the characteristic polarisation state method is proposed to determine egg quantity in a box with a two by three egg configuration. Parameters are investigated for different egg quantity scenarios and the results show a potential way to determine number in terms of characteristic angle β.
Natural resonant frequency extraction for concealed weapon detection at millimetre wave frequencies
The concealed weapon detection approach proposed in this paper is based on the extraction of the CNR (complex natural resonance) frequencies. An interrogating pulse is sent to the target under detection, thus its unique transient response associated with target geometry and material property is obtained. Complex natural resonant frequencies of a certain target are waveform and incidence aspect independent, and can be extracted from its late time response. The beginning of the late time response is estimated based on the distance between the interrogating source and the target, the dimension of the target and the width of interrogating pulse. The proposed procedure is numerically verified by using CST microwave studio and the optimization program - the genetic algorithm. Simulated results are compared with analytical solutions with good agreement. The procedure is readily applied to complex objects such as a handgun or knife. (5 pages)
An analytical approach to the design of electrodes in high-power, fast-transverse-flow CO2 lasers
Abstract Usually, the design of the electrodes of fast-transverse-flow CO 2 lasers relies more on experimental data than on theoretical analysis. Traditional systems sustain a stable, high-power discharge but the current distribution generates a peaked, non-uniform small-signal-gain pattern. We present a theoretical model suitable for the design of electrodes that achieves a quasi uniform gain distribution. The analysis, based on a two-temperature model and the gas-transport equations, computes the electron density that supports a flat gain pattern. Combining the desired electron density with the electron-balance equations, the model determines the required electric field. The results were used to design a new set of electrodes for a home-made fast transverse flow CO 2 laser. A stable, large volume discharge ( 4 × 8 × 90 cm 3 ) with very good uniformity was obtained. The resulting gain distribution was registered in a bi-dimensional map. The peak gain rose from 1.2 m - 1 , attained with the old electrode set, to 1.6 m - 1 with the new one and the gain showed a homogeneous profile.