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1996 Vol. 18, No. 4
Display Method:
1996, 18(4): 337-343.
Abstract:
Based on the unit quaternion decomposition of rotation matrix, this paper puts forward an algorithm to estimate motion parameters from the space position vectors of 3D feature points. Rotation matrix s representation with the unit quaternion has no singular points, so the unit quaternion-based estimation method is of more practical importance, and the algorithm in this paper does not need iteration computation compared to those unit quaternion-based method proposed by Horn(1987) and Su, et al.(1989). Solutions uniqueness analysis of the algorithm and simulation experiment results are also presented, it can be seen that performance of the proposed method is satisfactory.
Based on the unit quaternion decomposition of rotation matrix, this paper puts forward an algorithm to estimate motion parameters from the space position vectors of 3D feature points. Rotation matrix s representation with the unit quaternion has no singular points, so the unit quaternion-based estimation method is of more practical importance, and the algorithm in this paper does not need iteration computation compared to those unit quaternion-based method proposed by Horn(1987) and Su, et al.(1989). Solutions uniqueness analysis of the algorithm and simulation experiment results are also presented, it can be seen that performance of the proposed method is satisfactory.
1996, 18(4): 344-348.
Abstract:
In array signal processing, 2-D spatial-spectrum estimation is required to determine DOA of multiple signals. A circular array of sensors is found to possess several nice properties for DOA estimation of wide-band sources. C. Usha Padmini et al. (1994) have suggested that there is no frequency-direction ambiguity in azimuth estimation for wide-band signals by using a circular array, even without the use of any tap delay elements. In 2-D spatial-spectrum estimation for wide-band signals, we find that it is impossible to avoid the ambiguity in source frequency-elevation angle pairs using a circular array. In this paper, interpolated circular arrays are used to perform 2-D spatial-spectrum estimation for wide-band sources. In the estimation, a large aperture circular array (r min/2) is found to possess suprior resolution capability and robustness.
In array signal processing, 2-D spatial-spectrum estimation is required to determine DOA of multiple signals. A circular array of sensors is found to possess several nice properties for DOA estimation of wide-band sources. C. Usha Padmini et al. (1994) have suggested that there is no frequency-direction ambiguity in azimuth estimation for wide-band signals by using a circular array, even without the use of any tap delay elements. In 2-D spatial-spectrum estimation for wide-band signals, we find that it is impossible to avoid the ambiguity in source frequency-elevation angle pairs using a circular array. In this paper, interpolated circular arrays are used to perform 2-D spatial-spectrum estimation for wide-band sources. In the estimation, a large aperture circular array (r min/2) is found to possess suprior resolution capability and robustness.
1996, 18(4): 349-353.
Abstract:
Many high resolution methods such as MUSIC rely on a signal subspace decomposition, which is conventionally accomplished by an eigendecomposition. However an eigendecomposi-tion is very computationally intensive and difficult to implement. In this paper, by using the special structure of the covariance matrix, a fast high resolution method based on QR decomposition is presented. In most case, the performance of the new method is similar to those of MUSIC method, but the new method has smaller computational complexity and easier for parallel implementation.
Many high resolution methods such as MUSIC rely on a signal subspace decomposition, which is conventionally accomplished by an eigendecomposition. However an eigendecomposi-tion is very computationally intensive and difficult to implement. In this paper, by using the special structure of the covariance matrix, a fast high resolution method based on QR decomposition is presented. In most case, the performance of the new method is similar to those of MUSIC method, but the new method has smaller computational complexity and easier for parallel implementation.
1996, 18(4): 354-361.
Abstract:
In image restoration, the directions of the details are random. By standard median filter, the central pixel is processed as well as others, but in fact, the central pixel and it s neighbourhoods act as different role from others. To solve the above two problems, omnidirectional bell-shaped weighted median filters are proposed. The filter s convergence properties are proved. For noise standard image the comparison between the filter proposed in this paper and other median filters are made. The results show that the proposed filter performs better than others.
In image restoration, the directions of the details are random. By standard median filter, the central pixel is processed as well as others, but in fact, the central pixel and it s neighbourhoods act as different role from others. To solve the above two problems, omnidirectional bell-shaped weighted median filters are proposed. The filter s convergence properties are proved. For noise standard image the comparison between the filter proposed in this paper and other median filters are made. The results show that the proposed filter performs better than others.
1996, 18(4): 362-368.
Abstract:
An adaptive line spectral pair filter is derived from an adaptive lattice filter. A least-mean-square(LMS) type adaptive algorithm used to calculate directly the line spectral pair coefficients on a stage-by-stage is proposed. Experimental results show that the algorithm has higher convergence rate and lower misadjustment as compared with other algorithms. Using LSP coefficients calculated by the algorithm, speech linear predictive synthesis work has been carried out, and better results have been obtained as compared with that using PARCOR coefficients.
An adaptive line spectral pair filter is derived from an adaptive lattice filter. A least-mean-square(LMS) type adaptive algorithm used to calculate directly the line spectral pair coefficients on a stage-by-stage is proposed. Experimental results show that the algorithm has higher convergence rate and lower misadjustment as compared with other algorithms. Using LSP coefficients calculated by the algorithm, speech linear predictive synthesis work has been carried out, and better results have been obtained as compared with that using PARCOR coefficients.
1996, 18(4): 369-376.
Abstract:
This paper proposes new hierarchical structures for generating pseudo-random sequences and arrays. The principle of the structures is based on a new concept-multi-interleaving, the generalization of normal sequence decimation(sampling). The kernel of the structure is a lower speed linear feedback shift register together with several high speed time-division multiplexers arranged hierarchically These new structures have much higher speed compared with that of other schemes proposed before.
This paper proposes new hierarchical structures for generating pseudo-random sequences and arrays. The principle of the structures is based on a new concept-multi-interleaving, the generalization of normal sequence decimation(sampling). The kernel of the structure is a lower speed linear feedback shift register together with several high speed time-division multiplexers arranged hierarchically These new structures have much higher speed compared with that of other schemes proposed before.
1996, 18(4): 377-384.
Abstract:
The performances of DQDB MAN with multiple priorities are analyzed. The expressions of mean message sojourn time in the buffer are derived. Computer simulations are consistent with the theoretical results.
The performances of DQDB MAN with multiple priorities are analyzed. The expressions of mean message sojourn time in the buffer are derived. Computer simulations are consistent with the theoretical results.
1996, 18(4): 385-390.
Abstract:
Firtly, spectral characterization of Boolean functions satisfying k order propagation criterion is discussed; secondly, spectral characterization of Boolean functions satisfying k order strict avalanche criterion is described; finally, the generalized e- k order propagation criterion is introduced and its spectral characterization is given.
Firtly, spectral characterization of Boolean functions satisfying k order propagation criterion is discussed; secondly, spectral characterization of Boolean functions satisfying k order strict avalanche criterion is described; finally, the generalized e- k order propagation criterion is introduced and its spectral characterization is given.
1996, 18(4): 391-396.
Abstract:
This paper presents a deep researching of the microwave characteristics of a quantum well laser diode with the diode s microwave S parameters. By considering the characteristics and microwave packing effects of the device, a microwave equivalent circuit of the semiconductor quantum well laser and the numerical analogous methods for it are proposed. By devoloping a proper object function and selecting a correct calculation method, the element parameters of the circuit are succesfully simulated under the measured microwave S11 parameters. By comparing the calculated results and the measured ones, it shows that presented equivalent circuit is correct and the calculation method is effective.
This paper presents a deep researching of the microwave characteristics of a quantum well laser diode with the diode s microwave S parameters. By considering the characteristics and microwave packing effects of the device, a microwave equivalent circuit of the semiconductor quantum well laser and the numerical analogous methods for it are proposed. By devoloping a proper object function and selecting a correct calculation method, the element parameters of the circuit are succesfully simulated under the measured microwave S11 parameters. By comparing the calculated results and the measured ones, it shows that presented equivalent circuit is correct and the calculation method is effective.
1996, 18(4): 397-400.
Abstract:
A new method of extracting BJT dynamic model parameters is proposed by using the correlation between dynamic and static model parameters. Finally, the feasibility and utility of the method are demonstrated.
A new method of extracting BJT dynamic model parameters is proposed by using the correlation between dynamic and static model parameters. Finally, the feasibility and utility of the method are demonstrated.
1996, 18(4): 401-407.
Abstract:
It is shown from the accelerated lifetime test and noise measurement for integrated operational amplifiers that if their failure is caused by the drift of input bias current or input offset current, the drift is strongly correlated with 1/f noise current in these devices, and both are proportional approximately. In the mechanism analysis, the drift may be attributed to the slow capture effect of oxide traps, which are 1/f noise sources, on the electrons in silicon. Therefore, 1/f noise measurement can be used as a fast and non-destructive tool to evaluate the long term instability of integrated operational amplifiers.
It is shown from the accelerated lifetime test and noise measurement for integrated operational amplifiers that if their failure is caused by the drift of input bias current or input offset current, the drift is strongly correlated with 1/f noise current in these devices, and both are proportional approximately. In the mechanism analysis, the drift may be attributed to the slow capture effect of oxide traps, which are 1/f noise sources, on the electrons in silicon. Therefore, 1/f noise measurement can be used as a fast and non-destructive tool to evaluate the long term instability of integrated operational amplifiers.
1996, 18(4): 408-414.
Abstract:
This paper discusses the definitions and properties of two kinds of fundamental symmetric functions, which are based on AND-OR-NOT algebraic system and AND-Exclusive OR algebraic system, respectively. Based on it, the mapping trasformation methods between two kinds of expansion coefficients of an arbitrary function in the complete sets of two fundamental symmetric functions are proposed.
This paper discusses the definitions and properties of two kinds of fundamental symmetric functions, which are based on AND-OR-NOT algebraic system and AND-Exclusive OR algebraic system, respectively. Based on it, the mapping trasformation methods between two kinds of expansion coefficients of an arbitrary function in the complete sets of two fundamental symmetric functions are proposed.
1996, 18(4): 415-421.
Abstract:
The electromagnetic inverse scattering problem governed by the fiest kind of Fredholm integral equation is an ill-posed problem. By the aid of a series of unrelated illuminations we may obtain more information about the considered object and then achive a stable moment solution. On the basis of the unrelated illumination method(UIM), the paper derived a general formula that is suitable for solving the electromagnetic inverse problem, of which the object to be reconstructed may be expanded in various sets of othogonal bases. The uniqueness of the solution has been proved.
The electromagnetic inverse scattering problem governed by the fiest kind of Fredholm integral equation is an ill-posed problem. By the aid of a series of unrelated illuminations we may obtain more information about the considered object and then achive a stable moment solution. On the basis of the unrelated illumination method(UIM), the paper derived a general formula that is suitable for solving the electromagnetic inverse problem, of which the object to be reconstructed may be expanded in various sets of othogonal bases. The uniqueness of the solution has been proved.
1996, 18(4): 422-425.
Abstract:
A multimedia, imaging, coherent CO2 laser radar is developed and tested. The multimedia laser radar systems can simultaneously display the target image and report the range and velocity data of the imaged target by sound. This paper reports the design and the construction of this system. The photograph of the laser radar imaging at a range of 1.1km is given.
A multimedia, imaging, coherent CO2 laser radar is developed and tested. The multimedia laser radar systems can simultaneously display the target image and report the range and velocity data of the imaged target by sound. This paper reports the design and the construction of this system. The photograph of the laser radar imaging at a range of 1.1km is given.
1996, 18(4): 426-430.
Abstract:
This paper has modified the tradictional threshold decomposition technique which is introduced for the analysis and implementation of nonlinear filter. This modified technique called generalized threshold decomposition (GTD) is better than the traditional one in the analysis and VLSI realization, and is proved by strict mathematical method. So the traditional threshold decomposition technique is improved greatly.
This paper has modified the tradictional threshold decomposition technique which is introduced for the analysis and implementation of nonlinear filter. This modified technique called generalized threshold decomposition (GTD) is better than the traditional one in the analysis and VLSI realization, and is proved by strict mathematical method. So the traditional threshold decomposition technique is improved greatly.
1996, 18(4): 431-434.
Abstract:
A fast matching thinning algorithm based on tracing all contours is presented. It produces better image skeleton with faster processing speed. Experimental results show that this method is effective.
A fast matching thinning algorithm based on tracing all contours is presented. It produces better image skeleton with faster processing speed. Experimental results show that this method is effective.
1996, 18(4): 435-438.
Abstract:
A Ka-band phase-locked source (PLS) is analyzed and studied in detail. The stability of the millimeter PLL and the theory of phase compensation are discussed. In the practical scheme, the double PLL is applied, and the key components, such as the stable-cavity bias-tuned VCO, high-order multiplier and low phase-noise microwave PLL are developed. The SMT and high density assembly assembly technology are utilized in structure. Finally the millimeter PLS possesses features of miniaturization and low phase noise and high frequency stability.
A Ka-band phase-locked source (PLS) is analyzed and studied in detail. The stability of the millimeter PLL and the theory of phase compensation are discussed. In the practical scheme, the double PLL is applied, and the key components, such as the stable-cavity bias-tuned VCO, high-order multiplier and low phase-noise microwave PLL are developed. The SMT and high density assembly assembly technology are utilized in structure. Finally the millimeter PLS possesses features of miniaturization and low phase noise and high frequency stability.
1996, 18(4): 439-442.
Abstract:
A new method was presented to improve organic diode current-voltage (I-V) characteristics by using doped p-type material. The organic diodes with one-layer poly (3-alkylthiophene) (PAn=8T) and PAn=8T doped with various amounts of poly (N-vinylcarbazole) (PVK) (Pan=8T/PVK) sandwiched between an indium/tin oxide (ITO) and an aluminium cathode were fabricated by spin coating onto ITO respectively. It was found that the I-V characterisitcs were improved by doping with PVK in PAn=8T diode, and it was known that the exponent of the fitting equation has a maximum value by the best fit power curve if the doped PVK amount is moderate.
A new method was presented to improve organic diode current-voltage (I-V) characteristics by using doped p-type material. The organic diodes with one-layer poly (3-alkylthiophene) (PAn=8T) and PAn=8T doped with various amounts of poly (N-vinylcarbazole) (PVK) (Pan=8T/PVK) sandwiched between an indium/tin oxide (ITO) and an aluminium cathode were fabricated by spin coating onto ITO respectively. It was found that the I-V characterisitcs were improved by doping with PVK in PAn=8T diode, and it was known that the exponent of the fitting equation has a maximum value by the best fit power curve if the doped PVK amount is moderate.
1996, 18(4): 443-448.
Abstract:
A simulation method with SPICE for pH-ISFET based sensors and their circuits is presented. Using the parameters of built-in MOSFET in SPICE and some voltage sources, pH versus sensitivity, transient response and temperature characteristic of pH-ISFET based sensors and their circuits are carried out and corresponded to experimental results.
A simulation method with SPICE for pH-ISFET based sensors and their circuits is presented. Using the parameters of built-in MOSFET in SPICE and some voltage sources, pH versus sensitivity, transient response and temperature characteristic of pH-ISFET based sensors and their circuits are carried out and corresponded to experimental results.
