Showing papers by "Harbin Engineering University published in 1999"
TL;DR: In this paper, the performance of a Faraday current sensing element with single medium layer coatings with potential for use at high voltage is reported, and the principle and the design parameters of the polarization-preserving, totally reflecting, single Medium layer are given.
Abstract: The performance of a Faraday current sensing element with single medium layer coatings with potential for use at high voltage is reported, and the principle and the design parameters of the polarization-preserving, totally reflecting, single medium layer are given. The performance of the sensing element is demonstrated, showing a sensitivity of approximately 90% of the theoretically achievable maximum for an ideal case, a ratio error of 0.33% over a 7 h stability period and a 21 dB EMI immunity. Some of the advantages of this design are considered and discussed.
24 citations
09 May 1999
TL;DR: In this paper, the authors proposed a method to design the ship's fin stabilizer roll attitude control system using H/sup 8/ control theory, and solved the problem of the fin stabilization system not matching H/Sup 8/control theory because of the characteristics of the control system.
Abstract: In the absence of random sea wave disturbance, roll attitude control has been used in engineering by means of a fin stabilizer. This paper proposes a method to design the ship's fin stabilizer roll attitude control system using H/sup 8/ control theory. The problem of the ship's fin stabilizer system not matching H/sup 8/ control theory because of the characteristics of the control system is solved. At the same time, a new method is proposed to solve the problem of the frequency system object almost matching the frequency band of random sea wave disturbance.
7 citations
16 Jun 1999
TL;DR: Today, there's a synergy beginning to form among neural nets, fuzzy logic and genetic algorithms, and some advantages obtained through the fusion of the FL, NNs and GAs are emphasized, and possible ways of combining the three are developed.
Abstract: Today, there's a synergy beginning to form among neural nets (NNs), fuzzy logic (FL) and genetic algorithms (GAs). This paper reviews developments in this respect. Many designs of knowledge-based and associated learning systems using the combination of NNs and FL abilities have been presented. Some methods for the integration of GAs with fuzzy systems are described. Afterwards, work on hybrid systems of GAs and NNs is discussed. Finally, some advantages obtained through the fusion of the FL, NNs and GAs are emphasized, and possible ways of combining the three are developed.
5 citations
TL;DR: In this paper, the stationary conditions of various kinds of variational principles are derived and the relational problems discussed, and the relation between variational and Hamiltonian principles with subsidiary conditions are discussed.
Abstract: By using the involutory transformations, the classical variational principle—Hamiltonian principle— of two kinds of variables in general mechanics is advanced and by using undetermined Lagrangian multiplier method, the generalized variational principles and generalized variational principles with subsidiary conditions are established. The stationary conditions of various kinds of variational principles are derived and the relational problems discussed.
4 citations
TL;DR: In this paper, the cyclic plastic strain energy was used as a damage variable and its mathematical model of transient response was established by means of the damage mechanical method, which is used for prediction of low cyclic fatigue life.
Abstract: In this paper, the cyclic plastic strain energy is acted as damage variable and its mathematical model of transient response is established. The nonlinear fatigue damage function is given by means of the damage mechanical method. The formula used for prediction of low cyclic fatigue life is obtained from this damage function which takes into acount the cyclic relativity of cyclic plastic strain energy. The low cyclic fatigue life predicted by this formula is in correspondence with the experimental results.
4 citations
09 May 1999
TL;DR: A method, which utilizes fuzzy logic theory and reinforcement learning for designing the three-dimensional local path planner for an autonomous underwater vehicle (AUV) and the planner realizes the self-learning of the fuzzy rules.
Abstract: Proposes a method, which utilizes fuzzy logic theory and reinforcement learning for designing the three-dimensional local path planner for an autonomous underwater vehicle (AUV). The planner realizes the self-learning of the fuzzy rules.
2 citations
11 Jan 1999
TL;DR: In this article, the authors used a white light fiber optic interferometer to sense and measure the temperature in a specimen concrete beam and found a direct relationship between the fiber deformation and the optical path variation of the fiber sensor.
Abstract: The development of a fiber optic dual use sensor for embedding in concrete structure or buildings are described. The sensing system could monitor the state of a structure during construction and throughout its working life. The embedded optical fiber sensor, at first, can be employed as a transducer for measurement the temperature of fresh concrete at early age. Then, the embedded fibers do not degrade during curing, and they bond strongly to the matrix. The permanently embedded fiber optic sensors offers the opportunity to monitor the strain or displacements associated with the opening of the micro-cracks of the concrete structures in its whole life. In our experiments, a white light fiber optic interferometer is used to sense and measurement the temperature in a specimen concrete beam. A direct relationship between the fiber deformation and the optical path variation of the fiber sensor is obtained. A calibration procedure is developed by which the optical signal is converted to displacements. The temperature test result are compared with a convenience thermal couple. Experiments involved embedment of the optical fiber in concrete beams. In order to investigate micro-crack opening displacement characteristics, the sensor was employed in a series of fracture test. Specimens were center-edge-notched and the fiber optic sensor with the gauge length L were embedded at the tip of the notch. This arrangement allowed for direct measurement of displacements associated with the opening of microcracks at the crack tip. Experimental results are presented and crack-tip opening displacement results are compared with crack-opening displacements measured by conventional transducers at the crack mouth.
1 citations
Journal Article•
TL;DR: In this paper, the authors analyzed the process of standard GA approaching steady state by Markov chain and derived the convergence rate with SGA parameters applied more universally and more practically, which can be used for references by the research of other global convergent GA's convergence and rate.
Abstract: The process of standard genetic algorithm (SGA) approaching steady state by Markov chain is analyzed in this paper. The expression of steady state distribution is given particularly. The convergence rate estimates connected with SGA parameters applied more universally and more practically are developed, which can be used for references by the research of other global convergent GA's convergence and rate.
1 citations
09 May 1999
TL;DR: In this article, a ship fin stabilizer's joint control system is proposed and studied, where a Kalman filter is used to estimate the state variables, on the basis of which this paper employs LQG control theory to design the system.
Abstract: A ship fin stabilizer's joint control system is proposed and studied. The paper studies modeling of the system by utilizing the weighing least square algorithm upon the fin stabilizer's hydrodynamics. Considering the stochastic measuring noise and practicability of engineering, the paper adopts a Kalman filter to estimate the state variables, on the basis of which this paper employs LQG control theory to design the system. Finally, simulation of the system is carried out, the result of which shows that the new project has more obvious efficiency than a traditional fin stabilizer regarding stabilization and saving power.
1 citations
TL;DR: In this paper, a new approach with fuzzy sliding-mode control and double-gene genetic algorithm is proposed for designing combined maneuvering control system of submarines in order to avoid the effect of chattering phenomenon and possess better performance.
TL;DR: In this paper, a one-dimensional fiber-optic sliding sensor is introduced, where a half-sliding rod has been used as the sliding transfer device, and an angled-mirror reflector has been glued on the half-rod center plane surface.
12 Oct 1999
TL;DR: Based on the analysis of the character of Chinese, syllable division and endpoint detection in a high noise environment is achieved using the time-frequency parameter (TFP) and robust speech features are extracted.
Abstract: Based on the analysis of the character of Chinese, syllable division and endpoint detection in a high noise environment is achieved using the time-frequency parameter (TFP). Using TFP with RASTA-PLP (Relative Spectral-Perceptual Linear Perception) and SDA (Static, Dynamic and Acceleration), robust speech features are extracted. The differences between classes and the similarities within classes are increased by setting up a multi-value threshold function. In the presence of 80-95 dB noise level recorded in a vessel compartment, the results demonstrate the good performance of the system, and the TOP3 recognition rate of 200 passwords is better than 95%.