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Showing papers by "Harbin Engineering University published in 2003"


Journal ArticleDOI
TL;DR: In this paper, two design rules for single-layer radar absorbing coating (RAC) were proposed to find the suitable electromagnetic parameters so as to satisfy the practical requirements of applied background of the coating.

169 citations


Journal ArticleDOI
TL;DR: In this article, the authors studied the initial boundary value problem of semilinear wave equations, and obtained new existence theorems of global solutions, and proved that for any e ∈ (0,d) (d is the depth of the known potential well) all solutions with initial energy E(0) satisfying 0 H 0 1 (Ω).

115 citations


Journal ArticleDOI
TL;DR: In this paper, a simple and controlled method, that is, by electroless plating, nickel has been deposited on the surfaces of silicon carbon nanoparticles, and the deposited nickel and silicon carbide nanoparticles are bound tightly.
Abstract: By a simple and controlled method, that is, by electroless plating, nickel has been deposited on the surfaces of silicon carbon nanoparticles. Energy dispersive spectrometry (EDS) spectra show that pre-treatments of the silicon carbide nanoparticles have an important influence on the effect of electroless nickel plating. Transmission electron microscopy images and EDS spectra of silicon carbide nanoparticles before and after electroless nickel plating reveal that nickel has been deposited on the surface of silicon carbide nanoparticles and the deposited nickel and silicon carbide nanoparticles are bound tightly.

77 citations


Journal ArticleDOI
TL;DR: A novel method using an amplifier with a cantilever and gold nanoparticles successfully to extend the length of the target for the specific and high sensitive detection of DNA was reported.

38 citations


Journal ArticleDOI
01 Jun 2003-Robotica
TL;DR: A novel Cobotic system with differential CVT is presented, which is significantly cheaper, simpler to control and more efficient than Cobots with S-CVTs.
Abstract: This paper presents a novel Cobotic system with differential CVT. The new system is significantly cheaper, simpler to control and more efficient than Cobots with S-CVTs. Both path-guidance and power-assist functions can be simply realized with the new system. Basic structures, kinematic and dynamic models, as well as control algorithms, which are essential for design, control synthesis and control of the system, are briefly presented in the paper.

37 citations


Journal ArticleDOI
TL;DR: In this paper, the nanocrystallization kinetics of Zr 41.2 Ti 13.8 Cu 12.5 Ni 10 Be 22.5 (at%) bulk metallic glass was investigated by differential scanning calorimetry (DSC) in the mode of continuous heating and isothermal annealing.

36 citations


Proceedings ArticleDOI
01 Jan 2003
TL;DR: In this article, the performance of the wet compression and regenerative (WCR) gas turbine was investigated and the calculated results indicated that not only a significant specific power can be obtained, but also is the WCR gas turbine an economic competitive option of efficient gas turbines.
Abstract: Thermodynamic performance of wet compression and regenerative (WCR) gas turbine are investigated in this paper. The regenerative process can be achieved by a gas/air (and steam) heat exchanger, a regenerator, or by a heat recovery steam generator and then the steam injected into the gas turbine. Several schemes of the above wet compression and regenerative cycles are computed and analyzed. The calculated results indicate that not only a significant specific power can be obtained, but also is the WCR gas turbine an economic competitive option of efficient gas turbines.© 2003 ASME

29 citations


Journal ArticleDOI
TL;DR: In this article, the authors presented the results of viscosity measurement in composite cure process using fiber-optic sensors, where the sensor signal can be used to monitor the process, detect the time when the viscoity of resin matrix is lowest and the end of the cure without calibration.

28 citations


Journal ArticleDOI
TL;DR: In this article, a multiplexed Mach-Zehnder and Fizeau tandem white light interferometric fiber optic sensing system permitting absolute length measurement in remote reflective sensor arrays is proposed.
Abstract: A novel multiplexed Mach–Zehnder and Fizeau tandem white light interferometric fiber optic sensing system permitting absolute length measurement in remote reflective sensor arrays is proposed. The sensor reflective signals characteristics have been analyzed and the relationship between light signals power and sensors total number was given for multiplexing potential evaluation. Experimentally, a three sensor array has been demonstrated.

26 citations


Journal ArticleDOI
TL;DR: In this article, a series of experiments on discharging water mist from low/moderate-pressure system on gasoline fires were carried out at the new full-scale burning facility, Poly U/USTC Assembly Calorimeter at Lanxi, Harbin, Heilongjiang China.
Abstract: Local professionals are quite worrying about whether a water mist fire suppression system (WMFSS) can extinguish afire rapidly. It was also suggested in the literature that discharging water mist, even under the design operating conditions, might not always control afire rapidly. To explore more on that, a series of experiments on discharging water mist from low/moderate-pressure system on gasoline fires were carried out at the new full-scale burning facility, Poly U/USTC Assembly Calorimeter at Lanxi, Harbin, Heilongjiang China. An interesting point identified for quick communication is that for some designs of fuel container, the liquid fire cannot be extinguished even when all the fuels were consumed.

22 citations


Journal ArticleDOI
TL;DR: In this paper, the minimum heat release rate for flashover in a compartment fire was investigated in a chamber with dimensions similar to that in the standard ISO9705 Room-Corner Fire test.
Abstract: Studies on minimum beat release rates for flashover in a compartment fire will be reported in this paper. Experiments were carried out in a chamber with dimensions similar to that in the standard ISO9705 Room-Corner Fire test. This chamber is located inside a new full-scale burning facility, the PolyU/HEU Assembly Calorimeter, at the remote areas of Northern China. This is a joint project between Department of Building Services Engineering, The Hong Kong Polytechnic University (PolyU) and the Harbin Engineering University (HEU) in Heilongjiang, China. Heat release rates were measured by the oxygen consumption method. Correlation equations on estimating the minimum heat release rates for flashover will be reviewed and compared with the experimental results. Results are useful in fire hazard assessment while implementing engineering performance-based codes.

Journal ArticleDOI
TL;DR: In this article, a novel technique for enhancing the multiplexing capability of low-coherence interferometric sensor array is proposed, which uses a fiber loop topology and allows for twice as many sensors as the conventional lowcoherence reflectometry system to be multiplexed.
Abstract: A novel technique for enhancing the multiplexing capability of low-coherence interferometric sensor array is proposed. The technique uses a fiber loop topology and allows for twice as many sensors as the conventional low-coherence reflectometry system to be multiplexed. Power budget and signal analyses for different sizes of sensor array are performed. A ten-sensor system was experimentally demonstrated and applied for quasi-distributed temperature measurement. An additional advantage of the technique is that it provides an extra degree of redundancy through the bidirectional interrogation of the sensor array and thus improves the system reliability.

Journal ArticleDOI
TL;DR: In this article, a quasi-standing wave and generalized half-wave loss were proposed for the double loss medium, and the superposition wave mechanism that is similar to standing wave in transparent medium was exposed.

Proceedings ArticleDOI
26 Oct 2003
TL;DR: An algorithm of additive audio watermarking based on SNR to determine a scaling parameter /spl alpha/ is proposed and it is demonstrated that the watermark is inaudible and the algorithm is robust to many operations of digital audio signal, such as resampling, cropping, low pass filtering, additive noise and so on.
Abstract: An algorithm of additive audio watermarking based on SNR to determine a scaling parameter /spl alpha/ is proposed The visually recognizable binary watermark image could be embedded in the original signal wavelet domain in the algorithm The intensity of embedded watermarks on the different audio segments can be modified by adaptively adjusting the scaling parameter /spl alpha/ Comparing to the algorithm without using SNR, the experimental results demonstrate that the watermark is inaudible and the algorithm is robust to many operations of digital audio signal, such as resampling, cropping, low pass filtering, additive noise and so on


Proceedings ArticleDOI
02 Nov 2003
TL;DR: The experiments have showed that the method based on HMM is effective to detect anomalistic behaviors and can be treated as a classification problem.
Abstract: The intrusion detection technologies of the network security are researched, and the technologies of pattern recognition are used to intrusion detection. Intrusion detection rely on a wide variety of observable data to distinguish between legitimate and illegitimate activities. Hidden Markov Model (HMM) has been successfully used in speech recognition and some classification areas. Since Anomaly Intrusion Detection can be treated as a classification problem, some basic ideas have been proposed on using HMM to model normal behavior. The experiments have showed that the method based on HMM is effective to detect anomalistic behaviors.

Journal ArticleDOI
TL;DR: The designed and synthesized amphiphilic aminated hypocrellin derivatives possess the highest photodynamic activity and the water solubility and the experiments in vitro and in vivo on the derivatives are under way at present.
Abstract: Hypocrellins, as a kind of novel phototherapeutic agents, have several advantages over the clinically used hematoporphyrin derivatives, including high-excited triplet state yield, high phototoxicity, low dark toxicity, and rapid metabolism. However, they exhibit little absorption in the photodynamic window (600–900 nm) and are not water soluble, which limits their application in photodynamic therapy. Sulfonated and metal-ioned hypocrellins have been designed and synthesized to improve their water solubility. Unfortunately, the water-soluble derivatives obtained exhibit lower photodynamic activity than the parent hypocrellins. Thiolated and aminated hypocrellins have also been designed and synthesized to enlarge their photoresponse. Among them, the aminated hypocrellins possess the highest photodynamic activity. We recently have further designed and synthesized some amphiphilic aminated hypocrellin derivatives. Thus, not only the photoresponse but also the water solubility is enhanced. The experimentsin vitro andin vivo on the derivatives are under way at present.

Journal ArticleDOI
Abstract: Diamond is widely applied in cutting and grinding tools as the hardest and anti-wear material. Coating diamond surface with suitable materials is an effective method to improve the adhesion between diamond and matrix. Corundum-coated diamond, a new kind of diamond abrasive is developed for resin bond grinding applications. Diamond grits are coated with the corundum micron powders by the binding of a kind of vitreous material. The very rough and spiny morphology of the coated grit gives outstanding bond retention in resin matrix and avoids the premature loss of diamond from tools. The strength and oxidation resistance of diamond grits improve due to the coating protection effect. Industrial test results show that the grinding efficiency with an abrasive wheel made with corundum-coated diamond grits increases by more than 30% and the life of the wheel increases by 30~35%. Introduction Diamond grits give superior cutting performance for machining of rock and other nonferrous materials. The great attentions have been focused on the wear of diamond-segmented tools and the choice of bond type [1-4]. However, the waste of expensive grits associated with premature loss from tools is unexpected for toolmakers and users. One effective way to improve the adhesion between diamond and matrix is to coat diamond surface with suitable materials. Two types metals are usually selected as coating materials. One is carbide-forming metal as titanium, tungsten etc, which can form chemical bond between diamond and metal matrix [5-9]. Diamond grits coated with above materials have been developed for metal bond tools. The other is the metal such as nickel or copper. The thick coating layer of the metal assists the retention of diamond grits by keying into the bond. Cu, Ni-coated diamond grits are suitable for resin bond application. The metal coating, like Cu or Ni, can mechanically grip the friable grit to reduce its pullout and improve the adhesive strength between the grit and resin bond, thereby increasing the tool life greatly. However, designed for resin bond grinding wheels, the irregular friable grit is necessary for self-sharpening ability, which ensures the presence of new sharp cutting edges and keeps free cutting. The thick tough coating lowers the grit friability and cutting efficiency. The aim of this paper is to seek a suitable coating material that possesses the advantages of Cu or Ni coating and has no hurts to self-sharpening property. A new method has been developed to coat diamond with corundum micron powders, which are of low toughness and high strength. It is hoped that the new coating can meet all above-mentioned requirements. The coating process and the properties of corundum-coated diamond are introduced in this paper. Experimental Coating Process. Diamond grits were mixed with fine borosilicate glass powders; a thin layer of glass powders homogeneously bound on diamond surface, and then covered with corundum micro-powders. Various sizes of corundum micro-powders were selected to determine the effect of corundum particles on the coating properties. Table1 shows the range of glass compositions. The Key Engineering Materials Online: 2003-09-15 ISSN: 1662-9795, Vol. 250, pp 94-98 doi:10.4028/www.scientific.net/KEM.250.94 © 2003 Trans Tech Publications Ltd, Switzerland All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications Ltd, www.scientific.net. (Semanticscholar.org-13/03/20,20:10:19) Key Engineering Materials Vols. 95 covered diamond grits were sintered at 800 for 1h, then the corundum-coated diamond was obtained. The phase composition of corundum-coated diamond was investigated by D/max-rB diffractometer using CuKα radiation. The compressive strength of the grits was measured by a single grit method. Thermogravimetry analysis (TGA) was used to measure the temperature under which oxidation took place on the coated grits. Table 1 The composite scope of vitreous bond [wt%] SiO2 B2O3 Al2O3 Li2O Na2O K2O MgO CaO ZnO 48~100 5~45 1~15 0~18 0~18 0~20 0~12 0~16 0~18 Results and Discussion Morphology and Phase Composition of Corundum-Coated Diamond. The morphology of coated diamond grits is shown in Fig.1. The original shape and surface texture of diamond grits can not be seen due to the corundum coating, and the very rough, spiny and nodular surface presents. Therefore, when the grits with the corundum coating are used in resin bond tools, excellent bond retention and long tool life may be expected. Fig.1 The morphology of corundum-coated diamond 30 35 40 45 50 55 60 65 70 75 80 0 500

Journal ArticleDOI
TL;DR: In this paper, Nanogold particles in different sizes, from 5 to 60 nm, were used to modify the surface of the quartz crystal microbalance (QCM) to increase the sensitivity of the DNA detection.
Abstract: Nanogold particles in different sizes, from 5 to 60 nm, were utilized to modify the surface of the quartz crystal microbalance (QCM). It was found that the gold-particle size of the modified QCM affects both the amount of the immobilization of the probe on the surface of QCM and the hybridization rate of the target DNA. 20 nm was determined to be the optimal size for the surface modification and it can maximally increase the sensitivity of the DNA detection.

Journal Article
TL;DR: In this article, a vector transducer is used to measure the sound energy flux from a source, it may effectively depress the isotropic noise, and perform DOA determination by means of low frequency signal.
Abstract: When a vector transducer is used to measure the sound energy flux from a source,it may effectively depress the isotropic noise, and perform DOA determination by means of low frequency signal. But in case of multi-sources, when a single vector transducer is used, due to the vector nature of sound energy flux, it is hard to distinguish different sources by spatial directional pattern. However, the intensity and orientation of different sources may be solved by means of system of equations, given by even order moments of wide band receiving sound pressure and partite velocity, even if the line spectrum characteristics of each source are unknown, provided the S/N ratio will be sufficiently high. In this paper, the formula and general consideration accuracy in case of double sources are also described.

Journal ArticleDOI
TL;DR: In this paper, the influence of the preparing parameters on the properties of particles was studied carefully during the first nitriding process and the optimum process was determined, and the mechanism of nanoparticle nucleation and growth, including phase-transformation, was revealed.
Abstract: Multiphase Fe/N nanoparticles were synthesized by means of chemical vapor reaction, the influence of the preparing parameters on the properties of particles was studied carefully during the first nitriding process. The optimum process was determined. Single phase γ ′-Fe 4 N was prepared by twice-nitriding. Multiphase iron-nitride really transforms γ ′-Fe 4 N nanoparticle of single-phase and uniform. Moreover, the mechanism of nanoparticle nucleation and growth, including phase-transformation, was revealed. In addition, the mircograph, particle size, physical phases, schemical constituents and magnetic properties before and after phase-transformation were characterized initially.

Journal ArticleDOI
TL;DR: In this paper, an analytical model was developed to evaluate the thermally induced apparent strain in fiber optic sensors embedded in cement-based composites, and the effects of thermal induced strain on embedded optical fiber were measured with a white-light fiber-optic Michelson sensing interferometer.

Journal ArticleDOI
TL;DR: In this article, a photoelectric signal obtained scheme via equator triangle pattern engraved on rotor is discussed and the mathematic model is deduced in the case which is deflexion between rotor axis and the coordinate frame of case.
Abstract: In this paper, a photoelectric signal obtained scheme via equator triangle pattern engraved on rotor is discussed and the mathematic model is deduced in the case which is deflexion between rotor axis and the coordinate frame of case. The deflexion error and coupling error under the situation are analyzed. Finally, three methods of engraving based on the spherical triangle pattern are presented. The error models of various methods are built up and the simulation curves are provided respectively. We have done the primary experiments on the surface of rotor using this method. It can be seen from the enlarged figures that the rim of the pattern is smooth and the demand of sensor resolution is satisfied by and large. The results of study supply reference for signal obtaining.

Journal ArticleDOI
TL;DR: In this paper, the authors investigated the dynamic stress concentration and scattering of SH-waves by bi-material structures that possess an interface elliptic cavity and derived the solution of the displacement field for an elastic half space with a semi-elliptic canyon impacted by an anti-plane harmonic line source loading on the horizontal surface.
Abstract: In this paper, the dynamic stress concentration and scattering of SH-waves by bi-material structures that possess an interface elliptic cavity are investigated. First, by using the complex function method, the Green’s function is constructed. This yields the solution of the displacement field for an elastic half space with a semi-elliptic canyon impacted by an anti-plane harmonic line source loading on the horizontal surface. Then, the problem is divided into an upper and lower half space along the horizontal interface, regarded as a harmony model. In order to satisfy the integral continuity condition, the unknown anti-plane forces are applied to the interface. The integral equations with unknown forces can be established through the continuity condition, and after transformation, the algebraic equations are solved numerically. Finally, the distribution of the dynamic stress concentration factor (DSCF) around the elliptic cavity is given and the effect of different parameters on DSCF is discussed.

Journal Article
01 Jan 2003-Robot
TL;DR: A decoupling controller and an approach to the allocation of thruster forces of an AUV are investigated first, then a fault-tolerant control approach under thruster fault is given, and results from computer simulation show that the precision of the fault- tolerance control approach is satisfactory.
Abstract: In order to insure that autonomous underwater vehicle completes the tasks successfully in unstructured and hazardous oceanic environment with the high pressure and low visibility, an efficient and effective fault-tolerant control system becomes imperative for AUVs. This paper discussed thrust fault-tolerant control technology for ZHISHUI Ⅲ AUV, designed at Harbin Engineering University. A decoupling controller and an approach to the allocation of thruster forces of an AUV are investigated first, then a fault-tolerant control approach under thruster fault is given. Results from computer simulation show that the precision of the fault-tolerant control approach is satisfactory.

Proceedings ArticleDOI
TL;DR: This paper addressed and designed algorithm to select a set of views to materialize in order to answer the most queries under the constraint of a given space and shows that the proposed algorithm gives a less complexity and higher speeds and feasible expandability.
Abstract: A Data Warehouse contains lots of materialized views over the data provided by the distributed heterogeneous databases for the purpose of efficiently implementing decision-support or OLAP queries. It is important to select the right view to materialize that answer a given set of queries. In this paper, we have addressed and designed algorithm to select a set of views to materialize in order to answer the most queries under the constraint of a given space. The algorithm presented in this paper aim at making out a minimum set of views, by which we can directly respond to as many as possible user’s query requests. We use experiments to demonstrate our approach. The results show that our algorithm works better. We implemented our algorithms and a performance study of the algorithm shows that the proposed algorithm gives a less complexity and higher speeds and feasible expandability.

Journal ArticleDOI
TL;DR: In this article, the photorefractive effect of Mn:KLN was enhanced because Mn 2+ or Mn 4+ existed in the crystal, which applied more donor and acceptor centers.

Book ChapterDOI
07 Dec 2003
TL;DR: The classification of network attack and the key technologies of IDS in the information security field are introduced and a multi-agent based architecture for network attack resistant system is proposed, which has the advantage of intelligent attack detection capability and better scalability.
Abstract: Network Attack Resistant is a highlighted topic of network security research in recent years, it offers real-time protection to systems and is considered as the second important method in network security defense beside firewall. But the existing intrusion detection system architectures have a number of problems that limit their scalability and efficiency. Firstly, this paper introduces the classification of network attack and the key technologies of IDS in the information security field, secondly discusses the agent technologies. On the basis of discussion, a multi-agent based architecture for network attack resistant system is proposed. This architecture can be easily extended and maintained, supporting the network attack resistant system. In addition, it can greatly enhance the whole system efficiency. Then we present the system implementation and experiments of the approach. Finally, we can draw the conclusion that this architecture has the advantage of intelligent attack detection capability and better scalability, and future work is discussed.

Journal Article
TL;DR: The classification criterion appeared in this paper can describe intelligent robot architectures more roundly in detail so that all kinds of architectures are differentiated clearly, which is helpful for the analysis and design of intelligent robot architecture.
Abstract: The traditional classification of intelligent robot architectures is not enough to discriminate all kinds of new arisen architectures.This paper presented the definition of intelligent robot architectures and their new classification,The seven representative architectures were summarized and analysed by time: hierarchical,subsumption, three-layer, self-organizing, distributed, evolutionary control and social robot architecture, in terms of the spatial-temporal distributing mode of intelligence, behaviors, information and control of the intelligent robot systems.The classification criterion appeared in this paper can describe intelligent robot architectures more roundly in detail so that all kinds of architectures are differentiated clearly,which is helpful for the analysis and design of intelligent robot architectures.

Journal Article
TL;DR: Through the double ensemble slide t detected method to proof the existence of mean value catastrophe in the number of accurate diagnosis in the development of SARS, the authors in this paper presented definitions of brittleness, brittle source and brittle receiver as well as the basic characteristics were given on the basis of introducing seven kinds of primary catastrophes of catastrophe theory, the occurrence and the development, which took place in China in spring of 2003, were directly analyzed by using cusp catastrophe model.
Abstract: Through the double ensemble slide t detected method to proof the existence of mean value catastrophe in the number of accurate diagnosis in the development of SARSIn this paper, definitions of brittleness, brittle source and brittle receiver as well as the basic characteristics were given On the basis of introducing seven kinds of primary catastrophes of catastrophe theory, the occurrence and the development of SARS, which took place in China in spring of 2003, were directly analyzed by using cusp catastrophe model According to the data from Ministry of Health PR China from April to May in 2003, catastrophic detection and analysis were made by taking Beijing as an example The detected method is double ensemble slide t detected method Through analyzing the tendency ness of the SARS, the coming tendency of SARS was predicted and the correctness of the method was proved Based on this analysis, the brittleness analysis was given by using brittleness theoryThe result of analysis is that the panic mind for SARS of the common people will have an effect on the stability of society if we don't take effective measures in time