Showing papers by "Chung Yuan Christian University published in 1989"

QRS feature extraction using linear prediction

Abstract: The use of linear prediction for analyzing digital ECG signals is discussed. There are several significant properties indicating that ECG signals have an important feature in the residual error signal obtained after processing by Durbin's linear prediction algorithm. The prediction order need not be more than two for fast arrhythmia detection. The ECG signal classification puts an emphasis on the residual error signal. For the QRS complex of each ECG, the feature for recognition is obtained from a nonlinear transformation which transforms every residual error signal to a set of three states pulse-code train relative to the original ECG signal. The pulse-code train has the advantage of easy implementation in digital hardware circuits to achieve automated ECG diagnosis. The algorithm performs very well in feature extraction in arrhythmia detection. Using this method, the studies indicate that the PVC (premature ventricular contraction) detection has at least 92% sensitivity for MIT/BIH arrhythmia database. >

Minimum fluidization velocity of binary mixtures

Abstract: The fast defluidization method was used to measure the minimum fluidization velocities of binary systems. Based on the experimental data obtained from the published literature and from this work, different correlations used for predicting the minimum fluidization velocities of binary systems were evaluated and compared. On a utilise la methode de defluidisation rapide pour mesurer les vitesses minimales de fluidisation de systemes binaires. A partir des donnees experimental deja publiees et d'autres obtenues dans les presents travaux, differentes correlations utilisees pour la prediction des vitesses minimales de fluidisation de systemes binaires ont ete evaluees et comparees.

A system for pulse measurement and analysis of Chinese medicine

Abstract: A robotic system for pulse diagnosis used in Chinese medicine is presented. Computer-controlled robotic fingers containing a set of three subminiature pressure sensors were used to detect pulses. Preliminary results showing the diagnostic potential of the system are presented and are regarded as promising. >

Fast algorithm for digital retinal image alignment

Abstract: An algorithm based on an automatic multistage, multiple-featured-based registration strategy has been developed to decrease the amount of computation and to increase the speed of alignment for digital retinal images. The retinal image is digitized and processed to detect the location of the optical disk as a coarse feature. The branch point of a retinal vessel is automatically set up as a template by multilevel vessel tracing with adaptive-thresholding, cavity-filling, neighborhood-averaging, and stem-thinning techniques. Flowcharts for the automatic template setup and image alignment are given. >

Optimal inventory policy with partial backordering

Abstract: This paper formulates an inventory stocking policy with partial backordering. An implicit assumption in most inventory control models is that when there is a shortage, either complete backordering or complete lost sales is assumed. Such an assumption is not always tenable in view of the different responses by customers during stockout. Others who assume a fixed ratio of backordering and lost sales encounter the complication of a non-convex cost function. When the cost function is non-convex, the equation formulated is unstable; hence the optimal value is rather tedious to find. In this paper the fraction of backordering and lost sales is constrained so that convexity can be assured by means of the Hessian matrix. In this way the search for the optimal solution is simplified.

Adsorption equilibrium of xylene isomers and p-diethylbenzene in the liquid phase on a Y zeolite

Abstract: The saturated adsorptive capacity, adsorption equilibrium constant and adsorption isotherms of p-xylene, m-xylene, ethylbenzene (EB) and p-diethylbenzene (PDEB) on a K–BaY zeolite with n-heptane as...

The occurrence of superconductivity in the TlBa2CuO5−δ-type (1021) system

Abstract: Stable and reproducible superconductivity in the Tl(Ba2-xLax)CuO5-δ (0.0≤x≤0.6) system with the tetragonal TlBa2CuO5-δ-type (1021) structure was reported. A Prototype compound TlBa2CuO5-δ had shown a metastable superconducting onset around 25 K, with zero resistivity at 10 K. With partial substitution of La for Ba ions, Tc (50% resistivity drop) increases to 45 K, Tc0 (zero resistivity) to 42 K and onset around 50 K. A diamagnetic signal was observed with onset as high as 57 K. Tetragonal lattice parameters decrease with the increasing La concentration due to the partial replacement of larger Ba2+ ions by smaller La3+ ions. The Pairing field energy of 170 K and electron-elementary excitation coupling constant λ of 0.76 were derived from the BCS-like Tc formula through comparison with other single Tl-O layer systems TlCan-1Ba2CunO2n+3-δ.

Classification of QRS pattern by an associative memory model

Abstract: A feature-extraction method based on linear prediction for classification of QRS in an associative memory model is described. The feature extraction process converts each QRS pattern to a pulse-code train that describes only -1, 0, and +1 states. In order to recognize the feature of a QRS pattern, a two-layer feedforward neural net model is provided. The model shows the operation of each input node as well as a real neuron's three typical states: resting (0), excitatory (+), and inhibitory (-1). The model performs well for arrhythmia detection. >

Superconductivity enhancement in the (Tl,Pb)(A,R)2CuO5 system (A = Sr, Ba; R = La, Pr, Nd)

Abstract: Superconductivity enhancement in the calcium-free CuO 6 -octahedron (T1,Pb)(A,R) 2 CuO 5 systems (A = Sr, Ba; R = La, Pr, Nd) with the T1Ba 2 CuO 5 -type (1021)structure were reported. T c of 15 K and resistivity zero of 10 K was observed for the prototype compound T1Ba 2 CuO 5−† . Stable and enhanced T c up to 57 K was observed for the T1(Ba 2-x La x )CuO 5-δ system and up to 49 K for the (T1 0.5 Pb 0.5 )(Sr 2−x R x )CuO 5−δ (R = La, Pr, Nd) systems. Evidently the partial replacement of A 2+ ions by R 3+ ions is responsible for stabilizing and enhancing superconductivity in these systems.

Pattern recognition technique to QRS complex classification

Abstract: A pattern recognition method is presented for QRS-complex classification. The linear prediction method is used to extract feature vectors of ECG signal, and the error correction rule is used to obtain the exact weight vector by training some prototype feature vectors. Then, every feature vector of the QRS-complex is decided in each class by a linear discriminant function. The MIT-BIH database was used to evaluate the present algorithm, and the results of classification have precisions of over 99%. >

An efficient geometric curve fitting technique

Abstract: B-spline is a technique to trace out a smooth curve using a simple function and a set of control points. However, functional computation is usually more computationally costly than simple addition or multiplication. The Bezier method is more efficient as it is based on the geometric approach. The weakness of the Bezier method is its not passing through the control points. A geometric method is developed where a smooth, open or closed curve can be generated passing through all the control points. A weighting factor is introduced for variable curvature control of the curve to be generated. The number of points generated by the proposed method is 2/sup N-1/*(K-1), where K is the number of control points given, and N is the number of iterative steps taken. >

Measuring of Surface Roughness by Holographic Phase Shifting Interferometry

Abstract: An optical surface roughness measuring instrument has been developed which provides a noncontact method of obtaining surface characteristics of engineering surfaces. The system consists of a standard Twyman-Green interferometer controlled by a piezoelectric transducer, a linear array of photodiode detectors, and a microcomputer. The combination yields a system that measures the height variations of surfaces to a high degree of precision. Theoretical analysis and experimental systems are described. Surface roughness measurements are made in mirror, pre-coating surface, epoxy-painting surface, and fine-machined aluminium surface. Experimental results show that the measuring range of the sensitivity is from below 0.001 μm up to 2 μm rms. Due to the ability of high precision and fast measurement speed, an on-line metrological tool for roughness measurement of engineering surfaces can be developed.

Reconstruction of 3-D images of left ventricle from the rotating 2-D echocardiograms and calculating its volume

Abstract: A method of estimating left ventricular volume by echocardiography is proposed. It involves the use of an image processing technique to extract the cross-sectional shape. A method of finding the edge of the left ventricle and reconstructing its 3-D shape is presented. Comparison with reported results shows that the method is simple and accurate. >

An Efficient Synthesis of (.+-.)-Cuparene from 4,4-Dimethyl-2-cyclohexen-1-one.

Abstract: An efficient synthesis of (±)-cuparene 1 from 4,4-dimethyl-2-cyclohexen-1-one 2 involves 1,4-addition by use of organozinc reagent, ozonolysis and Dieckmann condensation as the key steps.