Showing papers by "Tongji University published in 1996"
25 Aug 1996
TL;DR: A recursive algorithm called Bhattacharyya distance feature selection for selecting a real-optimum feature under normal multidistribution is presented and the performance of the proposed algorithm is superior to any previous one.
Abstract: A recursive algorithm called Bhattacharyya distance feature selection for selecting a real-optimum feature under normal multidistribution is presented. The key of this method is to change the problem of minimizing the criterion of the sum of the upper bound of error probability of every two class pairs in subspace to a problem of solving a nonlinear matrix equation in a multiclass problem under an orthonormal coordinate system. The recursive algorithm is considered as finding the optimal solution of a transformation matrix from the nonlinear matrix equation. The theoretical analysis and experimental results show that under normal multidistribution the performance of the proposed algorithm is superior to the performance of any previous one.
72 citations
TL;DR: In this article, a hybrid approach based on the analysis of an equivalent continuous medium and a discrete lumped mass system is presented for conducting dynamic analysis of stiffened coupled shear walls supported on foundations which are flexible rotationally, and in both the vertical and horizontal directions.
48 citations
TL;DR: In this paper, the Qiantangjiang Estuary can be divided into three sections: upper normal river section, middle estuary funnel, and lower estuary mouth, which are divided into four stages: Last Glaciation (20,000-15,000 yr B.P.), formation of incised paleovalley.
Abstract: The tide-dominated Qiantangjiang Estuary can be zoned into three sections: upper normal river section, middle estuary funnel, and lower estuary mouth. Strong rejuvenation and incision of the Qiantangjiang River formed a type I sequence boundary and a paleovalley in the last glaciation. During the subsequent transgression and highstand, the incised paleovalley was filled and flooded, forming a complete lowstand-transgression-highstand sedimentary sequence including sequence boundary, lowstand systems tract, transgressive systems tract, maximum flooding surface, and highstand systems tract. The fluvial-channel sandy gravels and gravelly sands at the bottom of the Qiantangjiang incised paleovalley are composed of early lag sediments deposited during river incision, and later aggradational sediments resulted from baselevel rise whose demarcation is the transgressive surface. The aggradational sediments are distinct from the lag sediments in their aggradational parasequence assemblage, fining.up. ward sequence, and relatively later formation. The formation and evolution of the Qiantangjiang Estuary can be divided into four stages: Last Glaciation (20,000-15,000 yr B.P.): formation of incised paleovalley. (2) Early postglacial transgression (15,000-7500 yr B.P.): filling of the paleovalley. (3) Maximum transgression (7500-6000 yr B.P.): formation of the bay. (4) Highstand period (6000 yr B.P. to present): evolution of the estuary. Qiantangjiang River sediments contribute only a small part of the enormous volume of deposits trapped in the Estuary, whereas the adjacent Yangtze River is an indirect supplier of major sediments. The specific characteristics of the sedimentary sources in the estuary result in its unique sediment pattern, i.e., sandy gravels, gravelly sands, fine sands, and muddy sands from upstream to downstream, which is obviously different from the normal coarse-fine-coarse sediment distribution pattern in estuarine areas.
43 citations
TL;DR: In this article, the authors provided a comprehensive theoretical treatment of the eigenstrain problem of a spherical inclusion with an imperfectly bonded interface, where both tangential and normal discontinuities at the interface were considered and a linear interfacial condition was adopted.
Abstract: This article provides a comprehensive theoretical treatment of the eigenstrain problem of a spherical inclusion with an imperfectly bonded interface. Both tangential and normal discontinuities at the interface are considered and a linear interfacial condition, which assumes that the tangential and the normal displacement jumps are proportional to the associated tractions, is adopted. The solution to the corresponding eigenstrain problem is obtained by combining Eshelby's solution for a perfectly bonded inclusion with Volterra's solution for an equivalent Somigliana dislocation field which models the interfacial sliding and normal separation. For isotropic materials, the Burger's vector of the equivalent Somigliana dislocation is exactly determined ; the solution is explicitly presented and its uniqueness demonstrated. It is found that the stresses inside the inclusion are not uniform, except for some special cases.
41 citations
TL;DR: In this article, a laboratory-scale investigation was conducted to examine the effectiveness of the anaerobic upflow blanket filter (UBF) process for the biomethanation of a brewery effluent.
40 citations
TL;DR: In this article, the performance of sequencing-batch reactors (SBRs) for the treatment of three kinds of wastewater (synthetic phenolic wastewater, synthetic wastewater containing polyvinyl alcohol (PVA), and effluent from a coke-plant-wastewater treatment system) was investigated.
32 citations
TL;DR: In this article, the experimental results of a sequencing batch reactor (SBR) with aerated fill and an SBR with unaerated fill treating synthetic phenolic wastewater under identical conditions of influent phenol concentration and aeration time were presented.
24 citations
TL;DR: In this article, two methods to determine the equivalent modal damping ratios of a composite tower under wind-induced vibrations are presented, one using a detailed numerical integration procedure in which the static condensed stiffness matrices of the upper and lower substructures are established by the transfer matrix method.
21 citations
Patent•
25 Sep 1996
TL;DR: In this article, a direct current is passed through the water between an anode and a cathode to give a charge of 30 to 60 Coulomb per litre of water.
Abstract: The disclosure relates to a process for treating water contaminated with micro-organisms and/or harmful pollutants. A direct current is passed through the water between an anode and a cathode. The anode is provided with a coating containing titanium dioxide. The direct current is set to give a charge of 30 to 60 Coulomb per litre of water. The direct current has a catalytic effect promoting the loss of electrons from the titanium dioxide and the formation of oxygen radicals in the water. The process has a deposition effect promoting the disinfection of the water. The duration of that effect is proportional to the total electrical charge. The process also increases the quantity of dissolved oxygen in the water, which should be between 0.5 and 1.8 mg/l and is dependent specifically on the total charge in the water and on the anode material. Another effect of the process is a dramatic reduction in hard lime deposits on the cathode and in the water system as a whole.
16 citations
TL;DR: In this article, the power-law dependence of the scattered intensity, a characteristic of fractal structures, was observed for all the one-step aerogels derived from the two-step sol-gel process.
14 citations
TL;DR: In this article, the stresses of screw dislocation near an inclusion were analyzed based on the general theory of nonlocal elasticity and a maximum and a minimum of the shear stress were estimated in the dislocation core and near the inclusion.
TL;DR: In this article, the notion of functions α-starlike with respect to symmetric conjugate points was introduced and a convolution theorem in this class was derived, and a sharp coefficient estimate and a structural formula were given.
TL;DR: In this article, the history of change under deep water conditions and surface paleoproduclivity over the last 20, 000 years was reconstructed by using AMS 14C dating.
Abstract: Quantitative analyses have been carried out on benthic foraminifera from 66 samples of Core 255 in the southern Okinawa Trough, in combination with the stable isotopic analyses of planktonic and benthic foraminifera and AMS 14C dating, in order to reconstruct the history of change under deep water conditions and surface paleoproduclivity over the last 20 000 years. The variations in the ratio of agglutinants in benthic foraminiferal fauna and the ratio of fragments in planktonic foraminifera] fauna indicate higher carbonate dissolution during the postglacial stage than during the glacial stage. The distribution of species and the results of Q-mode factor analysis show that there are three distinctly different benthic foraminiferal assemblages during the glacial, deglacial and postglacial stages in the Okinawa Trough over the last 20000 years: the glacial Bulimina aculeata assemblage (especially the dominant species Uvigerina pereyrina) is associated with high surface primary productivity and organic matter content in sediments; the postglacial Uvigerina asperula assemblage corresponds to low surface primary productivity; while the deglacial Chilostomella colina assemblage possibly reflects low oxygen content in bottom water.
TL;DR: In this article, the structural transition from cubic to trigonal is one of second order and results from distortions with symmetry related to the irreducible representation at the point of the point.
Abstract: Raman spectra of and crystals have been recorded in the temperature range 5 K - 300 K. undergoes only one structural phase transition at from a cubic to a trigonal structure , whereas undergoes structural phase transitions from a cubic to a trigonal structure at , and to a monoclinic or orthorhombic structure at . Continuous changes of the Raman-active modes at in both compounds show that the structural transition from cubic to trigonal is one of second order and results from distortions with symmetry related to the irreducible representation at the point. Discontinuous behaviours of the Raman modes at in show that the second structural transition is one of first order.
02 Dec 1996
TL;DR: Simulation results have proved the validity of the HNN based AC drive system identification scheme and its adaptive control.
Abstract: In this paper, a Hopfield neural network (HNN) based open-loop and closed-loop AC drive system parameter identification scheme is derived. Then an autotuned AC drive system which has the ability of online parameter tracking is designed. Simulation results have proved the validity of the HNN based AC drive system identification scheme and its adaptive control.
25 Sep 1996
TL;DR: In this paper, the authors compared the spectra of open-circuit (OC) and short circuit (SC) TSD (Thermally Stimulate Discharge) measurements.
Abstract: The nonlinear optical material DR1/PMMA films were prepared by spin-coating method. The films were poled by constant voltage corona charging. Decay of surface potential was found to be slower at higher aging temperature (or poling) temperatures. The spectra of open-circuit (OC) and short-circuit (SC) TSD (Thermally Stimulate Discharge) were compared. One negative at 70/spl deg/C and one positive peaks at 100/spl deg/C were determined in open circuit TSD measurement. Only one negative broad peak appeared in short circuit TSD spectra. The OC first negative originated from the relaxation of polarization in the DR1/PMMA films, the second positive peak was due to the release of space charges. These two kinds of peaks usually emerge in polar materials. It indicated that the space charge was trapped to stabilize the polarization in polar materials. The second nonlinear optical effect and optical absorption in and near visible wavelength range was studied in the samples.
TL;DR: In this paper, the displacements and stresses for an orthotropic elasticity in plain strain condition are expressed in terms of two harmonic functions and the analysis of singularity at the tips of an edge crack is carried out.
Abstract: The displacements and stresses for an orthotropic elasticity in plain strain condition are expressed in terms of two harmonic functions. The analysis of singularity at the tips of an edge crack is carried out and the authors conclude finally that the singularity at the crack tips is the same as that in the corresponding axisymmetric problem
TL;DR: In this paper, the effects of spatial inhomogeneity in the one-dimensional quantum sine-Gordon model are treated by use of the variational Gaussian wave-functional method, and the properties of the ground state and the phase diagram of the system are investigated in detail.
Abstract: Effects of spatial inhomogeneity in the one-dimensional quantum sine - Gordon model are treated by use of the variational Gaussian wave-functional method. The properties of the ground state and the phase diagram of the system are investigated in detail.
TL;DR: In this paper, microfossils from the Malan Loess profiles, Miaodao Islands, have been quantitatively studied and the microfauna is composed mainly of benthic foraminifers together with a few planktonic fishes, ostracods, gastropods, bivalves and echinoid spines.
Abstract: Microfossils from the Malan Loess profiles, Miaodao Islands, have been quantitatively studied. The microfauna is composed mainly of benthic foraminifers together with a few planktonic foraminifers, ostracods, gastropods, bivalves and echinoid spines. With the exception of indigenous gastropods, benthic foraminifers, ostracods, bivalves and echinoid spines were transported from the north or northwest of the Bohai Sea in the glacial period by the prevailing winter monsoon, while planktonic foraminifers were probably driven from the Yellow Sea or even the northern East China Sea by southerly winds. The upward decrease of marine microfossil abundance and diversity in the Malan Loess profiles shows that the microfossil transportation occurred mainly at the beginning of the regression.
TL;DR: In this article, a stress and strength analysis of fibre reinforced plastic (FRP) tees using 3-D FEM is given. And the analysis shows that the stress concentration in tees with anisotropic material is greater than those in isotropic material under the same conditions.
25 Sep 1996
TL;DR: In this article, the behavior of charge storage in corona charged and electron-beam irradiated Teflon AF films is investigated, and the maximum potential of the free surface on the sample is directly proportional to the film thickness.
Abstract: The behavior of charge storage in corona charged and electron-beam irradiated Teflon AF films is investigated. Teflon AF film of 2 to 4 /spl mu/m thickness were prepared on glass substrates with Al and graphite electrodes by spin coating. Details of the experimental results are reported and discussed. For example, the measuring result of the laser-induced pressure pulse method shows that the velocity of the pressure pulse is 1.4 km/s. The maximum surface density depends mostly on the dielectric strength of the film, and the maximum potential of the free surface on the sample is directly proportional to the film thickness. The application of heat before, during or after charging can effectively improve the charge stability.
02 Dec 1996
TL;DR: This paper puts forward three proposals on the improvement of elevator control mode as far as the comfort is concerned, thus providing some basis and methods for the evaluation, manufacturing and control of the elevator.
Abstract: This paper attempts to analyze the elevator comfort through fuzzy comprehension evaluation, making use of fuzzy mathematics and various factors affecting the elevator comfort in general. Moreover, it puts forward three proposals on the improvement of elevator control mode as far as the comfort is concerned, thus providing some basis and methods for the evaluation, manufacturing and control of the elevator.
02 Dec 1996
TL;DR: A new identification method, called learning identification algorithm, of the model parameters of robot dynamics is proposed, which does not require the exciting trajectory, and the measurements of joint accelerations and velocities.
Abstract: In this paper, a new identification method, called learning identification algorithm, of the model parameters of robot dynamics is proposed. This method has the following features: it does not require the exciting trajectory, and the measurements of joint accelerations and velocities. The method is demonstrated experimentally by estimating the dynamic parameters of a shaped glass cutting robot.
TL;DR: In this paper, the optical transmittance of pressureless sintered KZr2P3O12 (KZP) ceramics was studied in the ultraviolet, visible light, and near infrared spectrum ranges.
Abstract: The optical transmittance of pressureless sintered KZr2P3O12 (KZP) ceramics was studied in the ultraviolet, visible light, and near infrared spectrum ranges. Thermal expansion, strength, and thermal shock resistance of the ceramics were also studied. KZP ceramics with different additives (0–8 wt% of MgO, ZnO or SrO) show a 30–70% transmittance from 0.4–2 μm, a low thermal expansion coefficient and high thermal shock resistance. These polyfunctional ceramics might be useful as optical windows.
02 Dec 1996
TL;DR: In this paper, a teamwork-based culture within a manufacturing setting is suggested, and the management and organization of multi-functional teams working under concurrent engineering conditions are described for short lead-time product development cycles.
Abstract: In order to maintain competitiveness in global markets, manufacturing organizations must reconsider current organizational designs. Team concepts, teamwork-based organization environment and enterprise cultures for concurrent engineering (CE) are studied as a solution to this need. In this paper the characteristics and definitions of the team are presented. A teamwork-based culture within a manufacturing setting is suggested. Moreover, the management and organization of multi-functional teams working under CE conditions are described for short lead-time product development cycles. The strategy for support the organization and structuring of project development teams is proposed. Finally, the teamwork system is discussed for CE supporting environment.
TL;DR: In this paper, a model for one-phase earth short circuits of a double-circuit high-voltage three-phase power transmission line (DHTT) and appropriate integration methods as well as the relevant computation scheme are described.
Abstract: New models are presented for one-phase earth short circuits of a double-circuit high-voltage three-phase power transmission line (DHTT) and appropriate integration methods as well as the relevant computation scheme are described. Simulation of the electromagnetic transients of the one-phase earth short circuit of the DHTT shows that using parallel processing, the models including their integration methods and computation steps are suited for real-time simulation of faults.
TL;DR: In this paper, a modified non-linear member element is derived which can lead to satisfactory computed results even for large loading and displacement increments from preinstability to post-instability of structures.
Abstract: In the paper a modified non-linear member element is derived which can lead to satisfactory computed results even for large loading and displacement increments from pre-instability to post-instability of structures. The high accuracy of this element is proved by numerical examples.
TL;DR: In this article, the molar ratios of Mg/Ca of ostracize shells are positively correlated with the temperature of the host water, but negatively correlated with its salinity.
Abstract: The μm-PIXE setup of Fudan University has been used to study the trace elements of ostracode shells. Program TSPIXE was used to calculate their trace element concentrations.Stenocypris derupta Vavra, Dolerocypria mukaishimensis okubo andTanella opima Chen, three kinds of ostracodes were analyzed. In this study, we concentrate on the relationships between molar ratios of Mg/Ca and temperature, and between molar ratios of Mg/Ca and salinity of the host water. We have found that the molar ratios of Mg/Ca of ostracize shells are positively correlated with the temperature of the host water, but negatively correlated with its salinity.
TL;DR: A new control scheme for robot visual tracking of a drawing curve (eye in hand configuration) with Transputer based parallel controller developed, which can reach 25cm/s with a small field of view, which is about 10 times higher than the conventional method.