Showing papers by "Southeast University published in 1996"
TL;DR: In this paper, a weighted non-radial CCR model with preference weights is proposed to consider the decision making unit's preference over the potential adjustments of various inputs and outputs when data envelopment analysis (DEA) is employed.
Abstract: It is important to consider the decision making unit (DMU)'s or decision maker's preference over the potential adjustments of various inputs and outputs when data envelopment analysis (DEA) is employed. On the basis of the so-called Russell measure, this paper develops some weighted non-radial CCR models by specifying a proper set of 'preference weights' that reflect the relative degree of desirability of the potential adjustments of current input or output levels. These input or output adjustments can be either less or greater than one; that is, the approach enables certain inputs actually to be increased, or certain outputs actually to be decreased. It is shown that the preference structure prescribes fixed weights (virtual multiplier bounds) or regions that invalidate some virtual multipliers and hence it generates preferred (efficient) input and output targets for each DMU. In addition to providing the preferred target, the approach gives a scalar efficiency score for each DMU to secure comparability. It is also shown how specific cases of our approach handle non-controllable factors in DEA and measure allocative and technical efficiency. Finally, the methodology is applied with the industrial performance of 14 open coastal cities and four special economic zones in 1991 in China. As applied here, the DEA/preference structure model refines the original DEA model's result and eliminates apparently efficient DMUs.
213 citations
TL;DR: A fast estimation method of the azimuth error /spl Phi//sub D/ is proposed for the initial alignment of SINS on stationary base, and the time of initial alignment is reduced greatly.
Abstract: In this paper a strapdown inertial navigation system (SINS) error model is introduced, and the observability of the SINS error model is analyzed. Then, on the basis of this SINS error model and the analysis of computer simulation results, a fast estimation method of the azimuth error /spl Phi//sub D/ is proposed for the initial alignment of SINS on stationary base. Consequently, the time of initial alignment is reduced greatly. The computer simulation results illustrate the efficiency of this fast initial alignment method.
140 citations
TL;DR: In this paper, the properties of positive solutions for three non-local reaction-diffusion problems are investigated and conditions on the existence and non-existence of global positive solutions are given.
Abstract: In this paper we investigate the properties of positive solutions for three non-local reaction-diffusion problems. The conditions on the existence and non-existence of global positive solutions are given. Moreover, we prove that the blow-up set is the whole region when the non-linearity occurs in the equation.
121 citations
TL;DR: In this paper, a simple model described by an autonomous continuous-time difference-differential equation with only one variable is presented, and chaotic behavior has been observed, dynamics of the system are analyzed briefly.
Abstract: In this letter we present a very simple model described by an autonomous continuous-time difference-differential equation with only one variable. By choosing suitable parameters and delay, chaotic behavior has been observed, dynamics of the system are analyzed briefly. This indicates that chaos can occur even in one-dimensional continuous-time systems with delay.
120 citations
TL;DR: In this paper, the authors generalize the characterization of Gorenstein flat modules over GNNs to n − FC rings (coherent rings with finite sdf−FP−injective dimension).
Abstract: In this paper, we generalize the characterization of Gorenstein flat modules over Gorenstein rings to n − FC rings (coherent rings with finite sdf−FP−injective dimension), and characterize n − FC rings in terms of Gorenstein flat and projective modules.
106 citations
TL;DR: In this paper, a geometric process model is introduced for the analysis of a two-component series system with one repairman, and the availability and the rate of occurrence of failure of the system are also determined.
Abstract: In this article, a geometric process model is introduced for the analysis of a two-component series system with one repairman. For each component, the successive operating times form a decreasing geometric process with exponential distribution, whereas the consecutive repair times constitute an increasing geometric process with exponential distribution, but the replacement times form a renewal process with exponential distribution. By introducing two supplementary variables, a set of partial differential equations is derived. These equations can be solved analytically or numerically. Further, the availability and the rate of occurrence of failure of the system are also determined. © 1996 John Wiley & Sons, Inc.
79 citations
TL;DR: In this paper, the effects of two types of surfaces sites (namely, silanol sites and amine sites) and their ratio on the characteristics of an Si3N4-gate pH-ISFET are discussed.
Abstract: Based on the site-binding model, the effects of two types of surfaces sites (namely, silanol sites and amine sites) and their ratio on the characteristics of an Si3N4-gate pH-ISFET are discussed. As the ratio β of silanol sites to amine sites is about 7 3 , the maximum of sensitivity of the electrolyte-insulator (E-I) interfacial potential versus the pH value, as well as of the range of linear response are theoretically obtained. The stability of pH-ISFET devices is partially determined by the total number of the two types of surface sites and their ratio. The theoretical results are shown to be supported by experimental results.
78 citations
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71 citations
TL;DR: In this article, the wear behavior of metal-matrix composites (MMCs) and that of the monolithic Al/12 wt% Si alloy was investigated in pin-on-disk tests from room temperature to 400 °C under dry conditions.
63 citations
02 Dec 1996
TL;DR: The derivatives of the cost with respect to pipe flows for water distribution system are deduced accurately for the first time and an efficient iterative algorithm for searching the optimum pipe flows is developed.
Abstract: Linear programming gradient (LPG) method is an important method for the optimum design of looped water distribution systems, but the complex algorithm and slow convergence restrict its applications. In this paper, the design of the looped water distribution system is considered as a linear programming with variable coefficients. The derivatives of the cost with respect to pipe flows for water distribution system are deduced accurately for the first time. An efficient iterative algorithm for searching the optimum pipe flows is developed. An example is presented. It is shown that the new algorithm has better convergence than present algorithms.
59 citations
TL;DR: A wavelet-based neural network with evolutionary programming is proposed that can provide a stochastic optimal search and experimental results are presented to show the potential of the evolutionary wavelet neural networks.
Abstract: A wavelet-based neural network with evolutionary programming is proposed. Unlike conventional backpropagation training algorithms, the evolutionary programming does not require gradient information and can provide a stochastic optimal search. Evolutionary programming is applied to optimise the wavelet neural network for function approximation. Experimental results are presented to show the potential of the evolutionary wavelet neural networks.
TL;DR: In this article, the formation of the plateaus on the stress-strain curves in TiNi shape memory alloy wires is discussed from the continuum mechanical point of view, where two metallurgical processes are considered to be essential: the parent phase and the martensite phase, separated by a phase interface which propagates along the wire when the wire is subjected to straining.
TL;DR: In this paper, it was shown that a ring R has an epic C-envelope if and only if C is closed under direct products and submodules, and if R is left T-coherent and pure injective as a right R-module.
Abstract: We prove the following results for a ring R . (a) If C is a class of right R -modules closed under direct summands and isomorphisms, then every right R -module has an epic C -envelope if and only if C is closed under direct products and submodules. (b) If R is left T -coherent and pure injective as a right R -module, then every T -finitely presented right R -module has a T -flat envelope, (c) Let R be a left T -coherent ring and injective right R -modules be T -flat. If every finitely presented left R -module has a flat envelope, then every T -finitely presented right R -module has a projective cover.
TL;DR: In this article, the estimation of target trajectory from passive sonar bearings and frequency measurements in the presence of multivariate normally distributed noise, with unknown inhomogeneous general covariance, is modeled as a nonlinear multiresponse parameter estimation problem and a Gauss-Newton type algorithm using only the first-order derivatives of the model function and a new convergence criterion is presented to implement such estimation.
Abstract: Estimation of target trajectory from passive sonar bearings and frequency measurements in the presence of multivariate normally distributed noise, with unknown inhomogeneous general covariance, is modeled as a nonlinear multiresponse parameter estimation problem. It is shown that maximum likelihood estimation in this case is identical to optimizing a determinant criterion which has a concise form and contains no elements of unknown covariance matrix. A Gauss-Newton type algorithm using only the first-order derivatives of the model function and a new convergence criterion, is presented to implement such estimation. The simulation results demonstrate that performance of the maximum likelihood estimation method with the above noise model is superior to that with the traditional noise assumption.
TL;DR: In this article, a milliMeter Wave (MMW) Doppler radar with grating structures for the applications of detecting speech signals has been discovered in our laboratory.
Abstract: MilliMeter Wave (MMW) Doppler Radar with grating structures for the applications of detecting speech signals has been discovered in our laboratory. The operating principle of detection the acoustic wave signals based on the Wave Propagation Theory and Wave Equations of The ElectroMagnetic Wave (EMW) and Acoustic Wave (AW) propagating, scattering, reflecting and interacting has been investigated. The experimental and observation results have been provided to verify that MMW CW 40GHz dielectric integrated radar can detect and identify out exactly the existential speech signals in free space from a person speaking. The received sound signal have been reproduced by the DSP and the reproducer.
TL;DR: The reinforcement of alloys with fibers can alter mechanical properties and affect their wear behavior as mentioned in this paper, and wear properties are critical to automotive industry applications as structural components of internal combustion engines.
Abstract: The Al-Si alloys are widely used for applications in the automotive industry as structural components of internal combustion engines. Wear properties are critical to these applications. The reinforcement of alloys with fibers can alter mechanical properties and affect their wear behavior.
TL;DR: In this paper, it was shown that the electroluminescent (EL) intensity of the shorter alkyl side chain poly(3-alkylthiophene) (P3AT) could be enhanced by blending a small amount of poly(N-vinylcarbazole) into P3AT in the emitting layer.
TL;DR: In this paper, a difference scheme was derived for a class of nonlocal parabolic equations with natural boundary conditions by the method of reduction of order and it was shown that the scheme is uniquely solvable and unconditionally convergent with the convergence rate of order O( h 2 + τ 2 ).
TL;DR: In this article, it was proved that every positive stationary solution is a thereshold when Ω is a ball and that there is at least one stationary solution if 2⩽n < 6.
TL;DR: In this article, a linear consecutive-2-out-of-n:F repairable system is studied, where the working time and repair time of each component are both exponentially distributed, and each component after repair is as good as new.
TL;DR: In this paper, a generalized finite-difference (FD) scheme combined with the measured equation of invariance (MEI) is presented for the analysis of electromagnetic scattering from an inhomogeneous and lossy chiral cylinder with electrically large, arbitrarily shaped cross section.
Abstract: A generalized finite-difference (FD) scheme combined with the measured equation of invariance (MEI) is presented for the analysis of electromagnetic scattering from an inhomogeneous and lossy chiral cylinder with electrically large, arbitrarily shaped cross section. A new FD mesh in both chiral and achiral regions is formed, and the FD equations in a chiral medium are derived; then a large sparse matrix is formulated. The numerical results of bistatic scattering width (two-dimensional radar cross section) are given for the chiral cylinders of rectangular, elliptical, and complex cross section, respectively. Some results are compared with available data.
TL;DR: In this paper, a parallel repairable model consisting of two units and one repairman is studied, where the working time and the repair time of the two units are all exponentially distributed.
Abstract: In this paper, a parallel repairable model consisting of two units and one repairman is studied. The working time and the repair time of the two units are all exponentially distributed. Assume that one unit after repair will be “as good as new”, but the other one not. By introducing the geometric process and using the method of supplementary variable, some important reliability indices are determined.
10 Nov 1996
TL;DR: A new capacitance extraction method named Dimension Reduction Technique (DRT) for 3D VLSI interconnects that converts a complex 3D problem into a series of cascading simple 2D problems, leading to the drastic reduction of the computing time and memory needs.
Abstract: In this paper, we present a new capacitance extraction method named Dimension Reduction Technique (DRT) for 3D VLSI interconnects. The DRT converts a complex 3D problem into a series of cascading simple 2D problems. Each 3D problem is solved separately, so we can choose the most efficient method according to the arrangement of conductors. More importantly, it is very easy to obtain the analytical solutions of 2D problem in many layers such as the pure dielectric layers and the layers with parallel signal lines. Therefore, the domain that has to be analyzed numerically is minimized. This leads to the drastic reduction of the computing time and memory needs. We have used the DRT to extract the capacitances of multilayered and multiconductor cross-overs, bends, via with signal lines and open-end. The results are in good agreement with those of Ansoft's SPICELINK and MIT's FastCap, but the computing time and memory size used by the DRT are several even tens times less than those used by SPICELINK and FastCap.
TL;DR: In this paper, the wear characteristics of Ni-Fe-W-S alloy layer under conditions of dry friction, i.e., with no lubrication at the contact surface and under heavy loads.
TL;DR: In this paper, a method used to determine the boundary conditions of the Finite Element Model of a slender beam with measured structure modal parameters is presented, and the results of calculation fully verify the effectiveness of the method offered and also verify that the accuracy is satisfying.
Abstract: In this paper, a method used to determine the boundary conditions of the Finite Element Model of a slender beam with measured structure modal parameters is presented. On deriving the method, the finite element model theory for dynamic calculating is used. Combined with the modal parameters from experiment, an FEM-modal parameter equation to determine the boundary conditions is put forward. For solving the equation, three methods are given. The first is the accurate method. The second is the full mode computation method by means of generalized inverse matrix. The third is the interpolation method of frequency. A numerical simulation with computer is given and the results of calculation fully verify the effectiveness of the method offered and also verify that the accuracy of the method is satisfying. Finally, an applied example is given and the results of calculation fully verify the effectiveness of the method offered.
TL;DR: A design scheme of variable structure adaptive control for linear time-invariant system with uncertain dynamics is proposed and the global stability of the overall system is proved.
TL;DR: In this paper, a transparent titanium dioxide film electrode with tetrasulfonated phthalocyanine (MTsPc) was used to obtain a photocurrent action spectroscopy.
Abstract: Absorption spectroscopy of tetrasulfonated Zn, Co, Ga, In, TiO and metal-free phthalocyanine on a transparent titanium dioxide film electrode, which is made up of interconnected particles and pores characterized by scanning electron microscopy, has been reported. The chemical modification of the TiO 2 microporous electrode with tetrasulfonated phthalocyanine (MTsPc) extends its absorbance into the visible region. The tetrasulfonated phthalocyanine mainly exists as the dimer on the TiO 2 microporous electrode. The photocurrent action spectroscopy shows that only the absorbance of the MTsPc monomer contributes to the photocurrent while that of the MTsPc dimer does not generate a photocurrent.
TL;DR: In this article, the effect of the quantum well near the surface of silicon is taken into account during field emission and an increase of the emission current due to the surface quantization of silicon and a reduction of emission currents due to a thin oxide layer is estimated using WKB approximation.
08 Sep 1996
TL;DR: Two fuzzy neural network architectures are presented to realize knowledge extracting from input-output samples and the experimental results have shown that the similar classification rules can be obtained in comparison to that of other fuzzy neural approaches with less number of rules and membership functions.
Abstract: Two fuzzy neural network architectures are presented to realize knowledge extracting from input-output samples. The network parameters including the necessary membership functions of the input variables and the consequent parameters are tuned and identified using evolutionary programming. The trained networks are then pruned so that the general rules can be extracted and explained. The experimental results have shown that the similar classification rules can be obtained in comparison to that of other fuzzy neural approaches with less number of rules and membership functions.
TL;DR: Rubbed polyimide films were investigated by Atomic Force Microscopy (AFM) as discussed by the authors, and microgrooves due to rubbing treatment were observed, whilst on a small scale, polyimides chain molecules were found to be non-uniformly oriented.
Abstract: Rubbed polyimide films were investigated by Atomic Force Microscopy (AFM). On a large scale, microgrooves due to rubbing treatment were observed, whilst on a small scale, polyimide chain molecules were found to be non-uniformly oriented. Liquid-crystal mono-layers were adopted in this study as visualizing media for AFM observation.