This paper presents the design and the experimental measurements of two complementary metal-oxide-semiconductor (CMOS) LC-tuned voltage controlled oscillators (VCO) implemented in a 0.18 μm 6-metal-layer mixed-signal...This paper presents the design and the experimental measurements of two complementary metal-oxide-semiconductor (CMOS) LC-tuned voltage controlled oscillators (VCO) implemented in a 0.18 μm 6-metal-layer mixed-signal/RF CMOS technology. The design methodologies and approaches for the optimization of the ICs are presented. The first design is optimized for mixed-signal transistor, oscillated at 2.64 GHz with a phase noise of -93.5 dBc/Hz at 500 kHz offset. The second one optimized for RF transistor, using the same architecture, oscillated at 2.61 GHz with a phase noise of -95.8 dBc/Hz at 500 kHz offset. Under a 2 V supply, the power dissipation is 8 mW, and the maximum buffered output power for mixed-signal and RF transistor are -7 dBm and -5.4 dBm, respectively. Both kinds of oscillators make use of on-chip components only, allowing for simple and robust integration.展开更多
The Oscillating Water Column(OWC) wave energy convertor with the advantage of its simple geometrical construction and excellent stability is widely employed.Recently,perforated breakwaters have been often used as they...The Oscillating Water Column(OWC) wave energy convertor with the advantage of its simple geometrical construction and excellent stability is widely employed.Recently,perforated breakwaters have been often used as they can effectively reduce the wave reflection from and wave forces acting on the structures.Considering the similarity between the compartment of perforated caisson and the air chamber of OWC wave energy convertor,a new perforated caisson of breakwater is designed in this paper.The ordinary caisson is modified by installing facilities similar to the air chamber of OWC converter,but here they are utilized to dissipate the wave energy inside the caisson.Such an arrangement improves the stability of the caisson and reduces the construction cost by using the compartment of perforated caisson like using an air chamber.This innovation has both academic significance and important engineering value.For a new type of caisson,reliability analysis of the structure is necessary.Linear potential flow theory is applied to calculate the horizontal wave force acting on the caisson.The calculated results are compared with experimental data,showing the feasibility of the method.The Importance Sampling Procedure(ISP) is used to analyse the reliability of this caisson breakwater.展开更多
The wave force exerted on vertical piles of offshore structures is the main criterion in designing them.In structures with more than one large pile,the influence of piles on each other is one of the most important iss...The wave force exerted on vertical piles of offshore structures is the main criterion in designing them.In structures with more than one large pile,the influence of piles on each other is one of the most important issues being concerned in past researches.An efficient method for determining the interaction of piles is introduced in present research.First the wave force is calculated by the exact method using the diffraction theory,then in the finite difference numerical method the force is calculated by adding the velocity potentials of each pile and integration of pressure on their surface.The results showed that the ratio of the wave force on each of the double piles to a single pile has a damped oscillation around unity in which the amplitude of oscillation decreases with the increase in the spacing parameter.Also different wave incident directions and diffraction parameters were used and the results showed that the numerical solution has acceptable accuracy when the diffraction parameter is larger than unity.展开更多
Structures of slender shape, like guyed masts, chimneys or TV towers, are exposed to the excitation of dynamic movements. The most common cause of vibration is the wind that reduces generation of vortices. Another imp...Structures of slender shape, like guyed masts, chimneys or TV towers, are exposed to the excitation of dynamic movements. The most common cause of vibration is the wind that reduces generation of vortices. Another important reason is a sudden strike from seismic or para-seismic forces. Structure exposed to wind impact is subjected to harmonically various force, perpendicular to the air stream, which is an effect of vortices, shedding on alternate sides of slructure. Because of the possibility of vibration the damping of a structure has to be designed. Measuring of decay in the oscillation allows to find the logarithmic decrement of the real structure and compare it with the designed value. Apart from damping, the proper designing of tall slender structures has to preserve the significant difference between vortex shedding frequencies and the natural frequencies of the structure shape modes. In the case of guyed masts it is important to analyse the response of a real structure to the exceptional dynamic load, such as a sudden break of guy or fall off a load from a structure, e.g., icing or antennas. The dynamic analysis of a real slructure requires the accurate values describing the dynamic behavior of tall structures （e.g., amplitudes）. The accuracy of 0.1 mm is provided by ground-based interferometric radar. This device is a part of the IBIS-S （image by interferometric survey） system, which calculates the displacement values on the basis of the difference between phases of waves received in consecutive samples. Typically, the measurements of tall structures are performed with several sensors （strain gauges, accelerometers）. Instead, the IBIS-S system allows the quasi-continuous （not limited to points） observation of the entire structure without installation of any sensors or reflectors. The real resolution （along the structure）, which means the minimum distance between two observed points, amounts up to about 0.7 m,展开更多
The air-gun source has important applications as a new, environmentally, green active source in regional scale deep exploration. In the past, the air gun source was used mainly in smallscale, high-resolution shallow o...The air-gun source has important applications as a new, environmentally, green active source in regional scale deep exploration. In the past, the air gun source was used mainly in smallscale, high-resolution shallow oil exploration, but has a lack of adequate research in deep exploration. In order to study the selection of work parameters and field conditions of the air gun source in deep exploration, this paper does the following work： （1） analyze the characteristics of the air gun source using air gun experiments; （2） simulate the air gun signal and air gun-array signal based on the theory of free bubble oscillation to analyze the influence of bubble oscillation and study the wavelet energy and spectrum characteristics needed in deep exploration; （3） on the basis of theoretical simulation, study the influence of work parameters, such as air-gun capacity, work stress and depth on air gun signal and analyze the influence of air-gun array inspired moment and spacing of different air guns on air gun-array signals; and （4） study energy reflection and transmission coefficients for different underwater interfaces, which is very useful for choosing suitable field conditions.展开更多
Experimental results of remote laser measurement of a time structure of a pulse waves are resulted. Occurrence of the pulse waves are connected with the rhythmic reduction of a myocardittm. Speed of pulse wave＇s prop...Experimental results of remote laser measurement of a time structure of a pulse waves are resulted. Occurrence of the pulse waves are connected with the rhythmic reduction of a myocardittm. Speed of pulse wave＇s propagation does not depend on speed of current of blood, it is defined by diameter of a vessel, by its walls thickness, by elasticity of a vessel, and also by rheological properties of blood. Measurement of parameters of pulse waves is important tbr definition of a condition of cardiovascular system. Ways of measurement of characteristics of pulse waves used now （acoustic, electric, optical） are contact. In some cases, for example, in clinics on treatment of burns and so forth, the question of remote measurement of processes hemodynamics by use of methods of laser sotmding is rather actual. The results described in work have shown outlook of development of laser methods of diagnostics for present purposes. The measurement technique used by authors is based on use of longitudinal Doppler effect which essence consists in change of frequency or length of a wave of radiation at reflection from moving surface. For smoothing the measured signal （clearing from noise） the program developed by authors on the basis of the wavelet-analysis was used. Experimental measurements are shown, that the laser method allows to register distinctly structure of pulse waves which is characterized by two peaks. The results of remote laser measurement of a time structure of a pulse waves confirm the assumption made on the basis of general-theoretical physical positions, that characteristics of pulse waves can be registered on the Doppler effect basis.展开更多
This paper proposes a one-branch zero-IF receiver topology, which samples the I and Q signals of the modulated RF carrier with one signal path by means of a multiphase local oscillator. The suggested one-branch re- ce...This paper proposes a one-branch zero-IF receiver topology, which samples the I and Q signals of the modulated RF carrier with one signal path by means of a multiphase local oscillator. The suggested one-branch re- ceiver works without matching problem, and it is also capable of cancelling out the flicker noise and DC-offset when the local oscillator is configured to the four-phase mode. The one-branch receiver saves much area and power com- pared with the traditional two-branch ones. All of the advantages above make the one-branch receiver topology a promising architectural candidate for low-power and low-cost RF CMOS receiver designs. Keywords： RF CMOS; zero-IF; flicker noise; image rejection; low-power; IQ matching展开更多
This paper contributes to the structural reliability problem by presenting a novel approach that enables for identification of stochastic oscillatory processes as a critical input for given mechanical models. Identifi...This paper contributes to the structural reliability problem by presenting a novel approach that enables for identification of stochastic oscillatory processes as a critical input for given mechanical models. Identification development follows a transparent image processing paradigm completely independent of state-of-the-art structural dynamics, aiming at delivering a simple and wide purpose method. Validation of the proposed importance sampling strategy is based on multi-scale clusters of realizations of digitally generated non-stationary stochastic processes. Good agreement with the reference pure Monte Carlo results indicates a significant potential in reducing the computational task of first passage probabilities estimation, an important feature in the field of e.g., probabilistic seismic design or risk assessment generally.展开更多
基金TheNationalHighTechnologyResearchandDevelopmentProgramofChina (863Program ) (No .2 0 0 2AA1Z160 0 )
文摘This paper presents the design and the experimental measurements of two complementary metal-oxide-semiconductor (CMOS) LC-tuned voltage controlled oscillators (VCO) implemented in a 0.18 μm 6-metal-layer mixed-signal/RF CMOS technology. The design methodologies and approaches for the optimization of the ICs are presented. The first design is optimized for mixed-signal transistor, oscillated at 2.64 GHz with a phase noise of -93.5 dBc/Hz at 500 kHz offset. The second one optimized for RF transistor, using the same architecture, oscillated at 2.61 GHz with a phase noise of -95.8 dBc/Hz at 500 kHz offset. Under a 2 V supply, the power dissipation is 8 mW, and the maximum buffered output power for mixed-signal and RF transistor are -7 dBm and -5.4 dBm, respectively. Both kinds of oscillators make use of on-chip components only, allowing for simple and robust integration.
基金supported by the National Natural Science Foundation of China (Grant No 4087-6047)
文摘The Oscillating Water Column(OWC) wave energy convertor with the advantage of its simple geometrical construction and excellent stability is widely employed.Recently,perforated breakwaters have been often used as they can effectively reduce the wave reflection from and wave forces acting on the structures.Considering the similarity between the compartment of perforated caisson and the air chamber of OWC wave energy convertor,a new perforated caisson of breakwater is designed in this paper.The ordinary caisson is modified by installing facilities similar to the air chamber of OWC converter,but here they are utilized to dissipate the wave energy inside the caisson.Such an arrangement improves the stability of the caisson and reduces the construction cost by using the compartment of perforated caisson like using an air chamber.This innovation has both academic significance and important engineering value.For a new type of caisson,reliability analysis of the structure is necessary.Linear potential flow theory is applied to calculate the horizontal wave force acting on the caisson.The calculated results are compared with experimental data,showing the feasibility of the method.The Importance Sampling Procedure(ISP) is used to analyse the reliability of this caisson breakwater.
文摘The wave force exerted on vertical piles of offshore structures is the main criterion in designing them.In structures with more than one large pile,the influence of piles on each other is one of the most important issues being concerned in past researches.An efficient method for determining the interaction of piles is introduced in present research.First the wave force is calculated by the exact method using the diffraction theory,then in the finite difference numerical method the force is calculated by adding the velocity potentials of each pile and integration of pressure on their surface.The results showed that the ratio of the wave force on each of the double piles to a single pile has a damped oscillation around unity in which the amplitude of oscillation decreases with the increase in the spacing parameter.Also different wave incident directions and diffraction parameters were used and the results showed that the numerical solution has acceptable accuracy when the diffraction parameter is larger than unity.
文摘Structures of slender shape, like guyed masts, chimneys or TV towers, are exposed to the excitation of dynamic movements. The most common cause of vibration is the wind that reduces generation of vortices. Another important reason is a sudden strike from seismic or para-seismic forces. Structure exposed to wind impact is subjected to harmonically various force, perpendicular to the air stream, which is an effect of vortices, shedding on alternate sides of slructure. Because of the possibility of vibration the damping of a structure has to be designed. Measuring of decay in the oscillation allows to find the logarithmic decrement of the real structure and compare it with the designed value. Apart from damping, the proper designing of tall slender structures has to preserve the significant difference between vortex shedding frequencies and the natural frequencies of the structure shape modes. In the case of guyed masts it is important to analyse the response of a real structure to the exceptional dynamic load, such as a sudden break of guy or fall off a load from a structure, e.g., icing or antennas. The dynamic analysis of a real slructure requires the accurate values describing the dynamic behavior of tall structures （e.g., amplitudes）. The accuracy of 0.1 mm is provided by ground-based interferometric radar. This device is a part of the IBIS-S （image by interferometric survey） system, which calculates the displacement values on the basis of the difference between phases of waves received in consecutive samples. Typically, the measurements of tall structures are performed with several sensors （strain gauges, accelerometers）. Instead, the IBIS-S system allows the quasi-continuous （not limited to points） observation of the entire structure without installation of any sensors or reflectors. The real resolution （along the structure）, which means the minimum distance between two observed points, amounts up to about 0.7 m,
基金sponsored by the National Natural Science Foundation of China (40730318 and 40574019)the key project of social welfare of the Ministry of Science and Technology,PRC(2005DIA3J117) +1 种基金seismic industry research project (200808002)basic scientific research of Institute of Geophysics CEA(DQJB07A01) ,China
文摘The air-gun source has important applications as a new, environmentally, green active source in regional scale deep exploration. In the past, the air gun source was used mainly in smallscale, high-resolution shallow oil exploration, but has a lack of adequate research in deep exploration. In order to study the selection of work parameters and field conditions of the air gun source in deep exploration, this paper does the following work： （1） analyze the characteristics of the air gun source using air gun experiments; （2） simulate the air gun signal and air gun-array signal based on the theory of free bubble oscillation to analyze the influence of bubble oscillation and study the wavelet energy and spectrum characteristics needed in deep exploration; （3） on the basis of theoretical simulation, study the influence of work parameters, such as air-gun capacity, work stress and depth on air gun signal and analyze the influence of air-gun array inspired moment and spacing of different air guns on air gun-array signals; and （4） study energy reflection and transmission coefficients for different underwater interfaces, which is very useful for choosing suitable field conditions.
文摘Experimental results of remote laser measurement of a time structure of a pulse waves are resulted. Occurrence of the pulse waves are connected with the rhythmic reduction of a myocardittm. Speed of pulse wave＇s propagation does not depend on speed of current of blood, it is defined by diameter of a vessel, by its walls thickness, by elasticity of a vessel, and also by rheological properties of blood. Measurement of parameters of pulse waves is important tbr definition of a condition of cardiovascular system. Ways of measurement of characteristics of pulse waves used now （acoustic, electric, optical） are contact. In some cases, for example, in clinics on treatment of burns and so forth, the question of remote measurement of processes hemodynamics by use of methods of laser sotmding is rather actual. The results described in work have shown outlook of development of laser methods of diagnostics for present purposes. The measurement technique used by authors is based on use of longitudinal Doppler effect which essence consists in change of frequency or length of a wave of radiation at reflection from moving surface. For smoothing the measured signal （clearing from noise） the program developed by authors on the basis of the wavelet-analysis was used. Experimental measurements are shown, that the laser method allows to register distinctly structure of pulse waves which is characterized by two peaks. The results of remote laser measurement of a time structure of a pulse waves confirm the assumption made on the basis of general-theoretical physical positions, that characteristics of pulse waves can be registered on the Doppler effect basis.
基金Supported by National Natural Science Foundation of China(No.60576026)
文摘This paper proposes a one-branch zero-IF receiver topology, which samples the I and Q signals of the modulated RF carrier with one signal path by means of a multiphase local oscillator. The suggested one-branch re- ceiver works without matching problem, and it is also capable of cancelling out the flicker noise and DC-offset when the local oscillator is configured to the four-phase mode. The one-branch receiver saves much area and power com- pared with the traditional two-branch ones. All of the advantages above make the one-branch receiver topology a promising architectural candidate for low-power and low-cost RF CMOS receiver designs. Keywords： RF CMOS; zero-IF; flicker noise; image rejection; low-power; IQ matching
文摘This paper contributes to the structural reliability problem by presenting a novel approach that enables for identification of stochastic oscillatory processes as a critical input for given mechanical models. Identification development follows a transparent image processing paradigm completely independent of state-of-the-art structural dynamics, aiming at delivering a simple and wide purpose method. Validation of the proposed importance sampling strategy is based on multi-scale clusters of realizations of digitally generated non-stationary stochastic processes. Good agreement with the reference pure Monte Carlo results indicates a significant potential in reducing the computational task of first passage probabilities estimation, an important feature in the field of e.g., probabilistic seismic design or risk assessment generally.
