Showing papers by "National Cheng Kung University published in 1980"
TL;DR: In this article, a combined method making use of the advantages of the stability-equation method and the continued-fraction method for reducing high order single-input/single-output systems and multivariate systems is presented.
Abstract: A combined method making use of the advantages of the stability-equation method and the continued-fraction method for reducing high order single-input/single-output systems and multivariate systems is presented. The reduction procedure is simple and computer-oriented. The reduced model is guaranteed to be stable if the original system is stable.
125 citations
TL;DR: In this article, a combined method making use of the advantages of the stability-equation method and the Pade approximation method for reducing high order transfer functions of single-input/single-output systems and multivariable systems is presented.
Abstract: A combined method making use of the advantages of the stability-equation method and the Pade approximation method for reducing high order transfer functions of single-input/single-output systems and multivariable systems is presented. The reduction procedure is simple and computer-oriented. All the reduced models are guaranteed to be stable if the original system is stable. The proposed method is applied to the investigation of (1) the effect of model reduction on the limit-cycle of non-linear systems and (2) the effect of model reduction on Horowitz compensators. Detailed calculations are given and comparisons with results in the current literature are made.
89 citations
TL;DR: In this article, the reaction order, the activation energy and the preexponential factor were evaluated from common TG curves experimentally obtained, in most cases a 5-mg sample of polystyrene with 110,000 molecular weight was decomposed at heating rate of 10°C/min.
Abstract: Various methods of thermogravimetric analysis were compared in case of polystyrene degradation. The reaction order, the activation energy and the preexponential factor were evaluated from common TG curves experimentally obtained. In most cases a 5-mg sample of polystyrene with 110,000 molecular weight was decomposed at heating rate of 10°C/min. The reaction was found under this experimental condition to be of first order with activation energy of 61.0 kcal/mole, though there were slight differences depending on the analytical methods used.
77 citations
TL;DR: In this paper, a combined method making use of the advantages of the stability-equation method and the Pade approximation method for finding stable reduced-order models is presented, and compared with the result in the current literature.
Abstract: A combined method making use of the advantages of the stability-equation method and the Pade approximation method for finding stable reduced-order models is presented. Comparisons with the result in the current literature are given.
69 citations
TL;DR: In this article, a linear time-invariant delay-differential equation system is represented by a set of linear algebraic equations with the block pulse functions, and a least square estimate is then used to determine the unknown parameters.
Abstract: Linear time-invariant delay-differential equation systems are approximately represented by a set of linear algebraic equations with the block pulse functions. A least squares estimate is then used to determine the unknown parameters. Examples with satisfactory results are given.
56 citations
TL;DR: In this article, local similarity solutions are obtained for the laminar boundary layer heat transfer along static and moving cylinders with prescribed surface temperature or wall heat flux, and the effects of normalized streamwise distance and Prandtl number on the temperature distribution and heat transfer rate are studied in detail.
Abstract: Local similarity solutions are obtained for the laminar boundary layer heat transfer along static and moving cylinders with prescribed surface temperature or wall heat flux. The effects of normalized streamwise distance and Prandtl number on the temperature distribution and heat transfer rate are studied in detail. The comparison with perturbation solutions is given. It is shown that the local similarity solutions are more useful for large normalized streamwise distance where the perturbation solutions are not valid.
54 citations
TL;DR: In this article, a new technique for harmonic reduction in inverters using sinusoidal pulsewidth modulation is presented, where the output wave with sinusoid pulsewidth distribution can be kept in maximum degree of symmetry, and so it offers excellent harmonic control in comparison with any other modulation technique.
Abstract: This paper presents a new technique for harmonic reduction in inverters using sinusoidal pulsewidth modulation. In this inverter, the output wave with sinusoidal pulsewidth distribution can be kept in maximum degree of symmetry, and so it offers excellent harmonic control in comparison with any other modulation technique. Detailed analysis shows that the harmonics lower than the ninth (or the thirteenth) are all less than one percent of the fundamental component when the number of pulses per half cycle is over seven (or nine). These results are confirmed by the theoretical data obtained from the natural sampling, and the experimental observations for single-phase full-bridge sinusoidal pulsewidth modulated (SPWM) inverters. It is concluded that by the use of this new technique it is quite easy to design an inverter with a distortion-free sinusoidal output.
35 citations
TL;DR: In this article, the effects of the electrical potential, temperature, pH value of electrolyte, and the propylene partial pressure on the current density were determined, and a mathematical model describing these reactions and the rates of determining steps were identified.
26 citations
TL;DR: In this paper, the heat transfer for the steady two-dimensional incompressible laminar boundary layer of power-law non-Newtonian fluids past a semi-infinite static or moving flat plate is studied.
Abstract: The heat transfer for the steady two-dimensional incompressible laminar boundary layer of power-law non-Newtonian fluids past a semi-infinite static or moving flat plate is studied by local similar...
15 citations
TL;DR: Based upon the dominant-torm concept, an inexpensive, fully digital, programmable waveform synthesizer lias beon designed and implemented and coincide with the results obtaind from computer simulation.
Abstract: The dominant-term concept in representing arbitrary functions using Walsh series is described. To verify dominant-term concept, a Fast Walsh Transform/Inverse Fast Walsh Transform (FWT/1FWT) subroutine following Brown's algorithm and an Approximato IFWT (AIFWT) subroutine have been written in FORTRAN IV and applied to various functions. The results obtained aro quito satisfactory. Based upon the dominant-torm concept, an inexpensive, fully digital, programmable waveform synthesizer lias beon designed and implemented. The various waveforms obtained from the aynthesiier coincide with the results obtaind from computer simulation.
15 citations
TL;DR: In this paper, a new flavonol, murrayanol, was characterized as 5,4′-dihydroxy-3,6,7,3′,5′-pentamethoxyflavone.
TL;DR: In this article, the boundary layer heat transfer for the steady two-dimensional incompressible combined laminar free and forced convection from a vertically static or moving plate to a power-law non-Newtonian fluid is analyzed by local similarity method.
Abstract: The boundary layer heat transfer for the steady two-dimensional incompressible combined laminar free and forced convection from a vertically static or moving plate to a power-law non-Newtonian fluid is analyzed by local similarity method. The effects of the flow index, buoyancy parameter, modified Prandtl number and streamwise distance on the heat transfer rate are discussed for the prescribed surface temperature and prescribed wall heat flux cases.
TL;DR: In this paper, the authors used population balance and residence time distribution models to evaluate the activity distribution for the catalysts in a well-mixed vessel with inlet catalysts of uniform or distributed activity.
TL;DR: In this paper, the apparent interdiffusion of counter-ions in anion exchange membrane Selemion ASV was investigated, and the experimental results showed that the rate of inter-interdiffusion is controlled by combined film diffusion and membrane diffusion at low flow rate, but controlled by membrane diffusion alone at high flow rate.
Abstract: The apparent interdiffusion of counter-ions in anion exchange membrane Selemion ASV was investigated. The experimental results show that the rate of interdiffusion is controlled by combined film diffusion and membrane diffusion at low flow rate, but controlled by membrane diffusion alone at high flow rate. The relationships between the apparent interdiffusion coefficient and temperature can be expressed by the Arrhenius equation for various systems. The apparent interdiffusion coefficient arid interdiffusion activation energy for various systems have the ordersDOH-Br>DOH-C1>DOH-NO3>DOH-I ?? DOH-SO4 AND EOH-Br SbOH-C1 SbOH-I, respectively. The interdiffusion of counter ions is independent of the kinds of co-ions at low concentration of the solution. There are an increase of integral interdiffusion coefficient and a decrease of interdiffusion activation energy with increasing bulk concentration of the electrolyte solution.
TL;DR: In this article, the uranyl chelate of ferron was investigated polarographically over the pH range 1.98-10.00 and ligand concentration 0.005-0.060.
Abstract: The uranyl chelate of ferron was investigated polarographically over the pH range 1.98–10.00 and ligand concentration 0.005–0.060.M. A reversible and diffusion controlled reduction wave was obtained, however, when ferron concentration below 0.02M and pH below 5.0, it became irreversible. The chelate species identified were UO2(HA) 2 at pH range 2.5–7.1 and UO2(OH) (A) 2−3 over pH 7.1. The electron-transfer coefficient, rate constant, diffusion coefficient and activation energy of the reduction process were determined.
TL;DR: In this paper, the boiling superheat without an active nucleation site decreased with the increase of the size of the water body and reached a constant value if it was sufficiently large.
TL;DR: In this paper, a special type linear variation wave function is associated with the SCF calculation, and the upper bound of the excited-state SCF can then be accessed by the help of this special wave function.
Abstract: One can treat the linear variation calculation by the perturbation expansion; on the other hand, one can also relate the perturbed wave function for the mth state to the mth eigenvector and justify the upper bound nature of the perturbation calculations for excited states. One can also associate a special type linear variation wave function to the SCF calculation. The upper bound nature of the excited-state SCF calculation can then be accessed by the help of this special wave function.
TL;DR: TCT was identified as a useful technique for measuring traffic safety and improvement and was developed by General Motors Research Laboratories.
Abstract: A traffic conflict is any potential traffic accident situation. A traffic control technique (TCT) was developed by General Motors Research Laboratories. As a result of this study, TCT was identified as a useful technique for measuring traffic safety and improvement.
TL;DR: In this article, the effect of external magnetic field on zero-field resonances was investigated analytically, and it was shown that the even-mode current height falls smoothly to zero as the external field strength is increased to nPhi/sub 0/2, where n is any positive integer and σ is the flux quantum.
Abstract: The effect of an external magnetic field on zero-field resonances is investigated analytically. A calculation shows that the even-mode current height falls smoothly to zero as the external field strength is increased to nPhi/sub 0//2, where n is any positive integer and Phi/sub 0/ is the flux quantum. A much more detailed comparison of the experimental observations and the theoretical predictions than that of earlier studies is given. We also discuss the temperature dependence of the current singularities and the formation of current branches with respect to coupling strength GAMMA in Fiske modes, a microwave-coupled resonance mode, and this zero-field case, and the spectrum of emission radiation of the zero-field resonant modes. A possible mechanism is proposed which differs from the conventional explanation for the zero-field resonances in terms of the vortex model suggested by Fulton and Dynes.
TL;DR: The theory formulated by Inglesfield based on the pseudopotential method was modified by the thermal lattice vibrations to interpret the explicit temperature dependence of the isomer shift in Sn 119.
TL;DR: In this paper, a power-series method is proposed to obtain analytical time responses of closed-loop systems containing irrational transfer functions such as exp(− s ), exp(√( s )) and exp[− s /( s + 1)].
TL;DR: In this paper, a multistage population balance model with a population balance for each stage is employed to evaluate the crystal size distribution in various continuous crystallizers, and the average population density for an imperfectly mixed crystallizer and the population density in a well-mixed crystallizer are found.
Abstract: The crystal size distribution in various continuous crystallizers is usually evaluated by the population balance model6>7). The population balance model is most advantageous for treating cases with crystal breakage. When a crystallizer is imperfectly mixed, a multistage model with a population balance for each stage is usually employed1>7). It is well known, however, that the residence time distribution of particles often cannot be fitted to a multistage model. The concept of residence time distribution has been used to find the average population density for an imperfectly mixed crystallizer2} and the population density in a well-mixed crystallizer4}. In the second case, the probability, which is actually the internal residence time function, of survival of crystal in a crystallizer is correlated with crystal size and growth rate. Miyauchi5) has employed the concentration
TL;DR: In this paper, the OPW method is used to study the temperature-dependent isomer shift of β-sn above the room temperature from the contributions including both the crystal pseudopotential with the Debye-Waller factor and the self-energy effect.