Showing papers by "Yanshan University published in 1996"
TL;DR: The analysis of the kinematic characteristics of 3 degrees-of-freedom (DOF) parallel actuated pyramid mechanisms using reciprocal screw theory finds several interesting features of the mechanisms.
100 citations
TL;DR: A high-accuracy and high-resolution fuzzy controller is designed to stabilize a double-inverted pendulum at an upright position successfully and a new idea of dealing with multivariate systems is described.
70 citations
TL;DR: The paper firstly discusses theoretically the relationship between the reciprocal screws and the motions of the mechanisms, then presents the analysis of the kinematic characteristics of several 3 DOF in-parallel actuated mechanisms.
65 citations
TL;DR: In this paper, a elastic-plastic finite strip method is presented to simulate roll-forming process by introducing the B-spline as its displacement function in longitudinal direction, this technique is suitable for simulating roll forming and easy to treat its boundary condition.
25 citations
TL;DR: In this paper, the authors employed the upper bound method to obtain theoretically sound approximations of the rolling force and torque for the estimation of the energy for the rolling process, with a high degree of accuracy.
9 citations
TL;DR: In this article, a low fineness fiber optic Fabry-Perot interferometric displacement sensor was developed and tested using a high performance He-Ne laser, low noise photodetectors, low drift operational amplifiers, 6-pole Butterworth filters and perfect digital signal processing circuits.
Abstract: A low fineness fiber optic Fabry-Perot interferometric displacement sensor has been developed and tested. With using a high performance He-Ne laser, low noise photodetectors, low drift operational amplifiers, 6-pole Butterworth filters and perfect digital signal processing circuits, a 0.005 nm displacement resolution is obtained.
6 citations
TL;DR: In this article, a new crystalline phase, Cu-rich phase, was discovered in nanocrystalline Fe73.5Cu1Mo3Si13.5B9 alloy at the optimum magnetic stage.
5 citations
TL;DR: In this article, a hybrid current sensor using a conventional current transformer is described, which converts the electric current flowing in the conductor at high potential and converts this signal to anoptical phase change in a novel differentiating optic fiber Mach-Zehnder interferometer.
Abstract: A new hybrid current sensor is described in this paper. The sensor uses a conventional current trans.former to sense the electric current flowing in the conductor at high potential and converts this signal to anoptical phase change in a novel differentiating optic fiber Mach-Zehnder interferometer. The optical signal isthen transmitted to ground potential for subsequent processing. By using the technique , aresolution of 0. 5A/4/i and an accuracy of 0. 7 % are obtained at the line frequency of 50 H and the dynamic range is1. 58--38OA in our prototype architecture.Keywords current sensor , interferometer , dynamic range 1. INTRODUCTION In power systems applications , fiber optic current sensor(FCS) attracts considerable interest in view ofthe well known characteristics of passive structure , intrinsic insulation , noninvasiveness , light weight , short installation time and improved performances (especially bandwidth) in respect to conventional device°. FCSis aimed to replace conventional current transformer(CT) on high-voltage(HV) lines, or to perform specialmeasurements (such as direct current measurements ,
5 citations
TL;DR: In this article, a closed two-stage queueing system with state-dependent vacation policy was considered and the authors derived both stationary distributions of the queue length and the cyclic time for the closed statedependent vacation model.
Abstract: This paper refers to some closed two-stage queueing systems with state-dependent vacation policy. By means of the markovian renewal process and the stochastic decomposition formulas of the quantities in equilibrium for M/G/1 vacation models, we derive both stationary distributions of the queue length and the cyclic time for the closed state-dependent vacation model. We try to solve the problems of closed systems by using the known results of the related opened Models, and for the purpose give an example in practice
3 citations
Journal Article•
TL;DR: In this article, a low finenesse Fabry-Perot interferometric displacement sensor was developed and tested with using a high stability He-Ne laser and perfect signal processing circuits.
Abstract: A low finenesse Fabry-Perot interferometric displacement sensor has been developed and tested With using a high stability He-Ne laser and perfect signal processing circuits, noise level of 0 01nm equivalent to reflector displacement was obtained in a bandwidth of 0-1 kHz
2 citations
TL;DR: Yanshan et al. as discussed by the authors proposed a method to solve the problem of people-to-government relations in China, which is based on the concept of people to people.
Abstract: yanshan univ,dept mat engn,qinhuangdao 066004,peoples r china.;yang, k (reprint author), acad sinica,inst met res,shenyang 110015,peoples r china
TL;DR: In this article, a new type of optical fiber pressure sensor is introduced and the ratio measurement by means of the sensing optical fiber and the reference fiber with different beginning positions and the technique to improve the stability of the sensor are first discussed.
Abstract: A new type of optical fiber pressure sensor is introduced in this paper. The ratio measurement by means of the sensing optical fiber and the reference fiber with different beginning positions and the technique to improve the stability of the sensor are first discussed. Then the ability to restrain and compensate the interference of the same nature through the double channel ratio measurement is illustrated. Finally, the performance of sensor and its engineering design are discussed.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Journal Article•
TL;DR: In this paper, the design of low-head CCM with two smooth continuous straightening areas is presented and the machine type presented by this paper is an absolute smooth curve It is of important significance for strand pass through without difficulty.
Abstract: This paper Presents the design of low-head CCM with two smooth continuous straightening areasInvolute is used as continuous straightening curve of first straightening area for the first time Continuous straightening curve of CONCAST is improved and acted as continuous straightening curve of second straightening area for the first time Therefor the machine type presented by this paper is an absolute smooth curve It is of important significance for strand pass through without difficulty
TL;DR: In this paper, the authors systematically derive coupled potential energy principle and complementary energy principle with two and three kinds of variables in photoelasticity by applying Lagrange multiplier method and high order Lagrange method.
Abstract: In this paper, by applying Lagrange multiplier method and high order Lagrange multiplier method [1], we systematically derive coupled potential energy principle, coupled complementary energy principle, and generalized coupled potential energy principles and generalized coupled complementary energy principles with two and three kinds of variables in photoelasticity.
TL;DR: In this article, fracture toughness properties of a simulated weld coarse grain heat affected zone (CGHAZ) in a newly developed 785 MPa grade high strength low alloy (HSLA) steel were investigated at different loading rates and a series of temperatures.
Abstract: Fracture toughness properties of a simulated weld coarse grain heat affected zone (CGHAZ) in a newly developed 785 MPa grade high strength low alloy (HSLA) steel were investigated at different loading rates and a series of temperatures. It is indicated that the fracture toughness K lc is a single-value function of the parameter ΔH=kT In (A/g), implying that just like the plastic deformation, the event of fracture initiation is also controlled by dislocation thermal activation movement.
TL;DR: In this article, a photoelectric system is devised in which an optimum diaphragm is chosen through measuring the optical transfer function of double-ringed diaphram in different dimensions.
Abstract: A simple photoelectric system is devised in this essay. An optimum diaphragm is chosen through measuring the optical transfer function of double-ringed diaphram in different dimension. In this way, it is proved that the quality of speckle pattern diffraction halos can be increased and a complex calculation can be avoided. The calculation and the photos provided here prove the reliability of the measurement.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: In this article, a trichromatic optical fiber radiation thermometer is used for non-contact accurate temperature measurement of those materials with the emissivities changing dramatically with wavelength.
Abstract: The study on trichromatic optical fiber radiation thermometers is especially useful for the non- contact accurate temperature measurement of those materials with the emissivities changing dramatically with wavelength. On the basis of the trichromatic thermometry principle, the operation wavelengths of the thermometer are selected properly so as to compensate the emissivity's influence on measurement result effectively. Using 1 X 3 branching fiber coupler and narrow band filter significantly improves the instrument's reliability. The instrument is self-calibrated, multi-functional and easy to use due to the embodied microcontroller and some other techniques.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: In this paper, the internal hydrogen embrittlement (IHE) of an α+γ duplex stainless steel has been investigated over the temperature range of 293-77K. The results showed that by lowering of testing temperature, the strength of the alloy increased obviously, but the elongation increased to 153k and decreased at lower temperature, while the area reduction decreased a little; at the same time, the H-induced loss of area reduction and elongation got the highest values at about 223K and decreased to almost zero at 77K.
Abstract: Mechanical properties and Internal Hydrogen Embrittlement (IHE) of an α+γ duplex stainless steel have been conducted over the temperature range of 293–77K. The results showed that by lowering of testing temperature, the strength of the alloy increased obviously, but the elongation increased to 153K and decreased at lower temperature, while the area reduction decreased a little; at the same time, the H-induced loss of area reduction and elongation got the highest values at about 223K and decreased to almost zero at 77K. Analyses on microstructure indicated that the formation of martensite could occur during deformation and /or decreasing of temperature, which would result in some increase in strength and the temperature dependence of ductility of the alloy at low temperature. However, the IHE behaviour of the alloy was found being dependant on both the formation of martensite and the diffusive ability of hydrogen.
TL;DR: In this paper, the effect of hydrogen on the phase constitution of super α2 alloy was studied by means of X-ray quantitative phase analysis, and the results showed that the alloy consists of α2, B2 and O phases.
Abstract: The effect of hydrogen on the phase constitution of super α2 alloy was studied by means of X-ray quantitative phase analysis. The results showed that the alloy consists of α2, B2 and O phases, and the volume fraction of O phase in the alloy increases with hydrogen content.