ANALYSIS AND DESIGN OF FEEDBACK CONTROL SYSTEMS WITH TRACKING ERRORS SQUARE

In this study, a command tracking error square control scheme is first proposed for analysis and design of feedback control systems. One of the tracking errors is low‐pass filtered and used in the feedback loop for gain adaptation; the other is used in the forward loop for command tracking control. The overall systems are nonlinear feedback systems, and can be reconfigured to an automatic gain control (AGC) loop with command tracking error input. The stability and robustness of the controlled systems are verified by time response, frequency response, and large parameter variation testing with a simple illustrating example and are finally applied to a complicated electro‐hydraulic velocity servo system with large load disturbance.     

Flexural response to impulsive loads of a fluid-saturated thin poroelastic circular plate

Biot's poroelastic theory is used with classic plate theory and plane stress theory to determine the constitutive relationships for a thin poroelastic plate. The dynamic equations for the thin poroelastic plate are derived from the extended Hamilton's principle. The dynamic equations are then transformed to frequency domain and Galerkin's finite element method is used to derive the stiffness matrix of a triangular plate element. When impulsive loads and elastic boundary conditions are applied, the finite element frequency domain analysis for the thin poroelastic plates is achieved. Vibration behavior of thin elastic and poroelastic circular plates is accurately predicted.     

Bibliometric analysis of the journal literature on women’s studies

This study uses bibliometric techniques to investigate the characteristics and implications of women’s studies literature over the period from 1900 to 2013. Using computer analysis for bibliometric techniques, the results of the present study demonstrate that the journal literature on women’s studies has grown exponentially, with an annual growth rate of 10.6% for over one century. Most of the document types in the area of women’s studies are in the form of research articles, review articles and book reviews. The United States of America and the United Kingdom contribute the largest number of articles. One hundred and seventeen core journals containing 33% of the women’s studies journal articles have been identified through the application of Bradford’s law on journal distribution. More than half of the 117 core journals began publishing from 1970 to 1990, and most of these core journals deal with the humanities (including literature, history and philosophy), women’s studies, medical science, psychology, political science and sociology. The highly productive journals associated with highly cited times are Signs: Journal of Women in Culture and Society, Women’s Studies International Forum, Sex Roles, Feminism and Psychology, Gender and Society, European Journal of Women’s Studies, American Historical Review, Psychology of Women Quarterly and Feminist Studies.     

Determinants of fast repeat migrations of the labor force: evidence from the linked national survey data of Taiwan

"The main objectives of this paper are (1) to identify the determinants of job-related fast repeat migrations of individuals in the civilian labor force of Taiwan, and (2) to examine whether the effects of these determinants are largely consistent with the existing theories and with the findings of other empirical studies. Our study is based on the linked microdata of the annual national migration surveys of Taiwan from 1980 through 1989.... We review the main theories of repeat migrations and formulate a set of hypotheses that can be tested against the Taiwanese data."     

The mechanism of cure of tetraglycidyl diaminodiphenyl methane with diaminodiphenyl sulfone

The curing reaction of tetraglycidyl diaminodiphenyl methane (TGDDM) with diaminodiphenyl sulfone (DDS) has been investigated using differential scanning calorimetry, Fourier transform IR spectroscopy, and ESR spin trapping techniques. A mechanism has been proposed, and the cure kinetics has been obtained at 177°C. The major conclusion is that cure proceeds mainly through chain extension, while crosslinking occurs through the reaction of hydroxyl groups with epoxides, resulting in formation of ether linkages.     

BAYESIAN ANALYSIS OF AUTOREGRESSIVE TIME SERIES VIA THE GIBBS SAMPLER

Abstract. Applications of the Gibbs Sampler in time series analysis are considered. We show that the sampler applies nicely to various problems in analyzing autoregressive processes and, in many cases, it enjoys certain advantages over the traditional methods. The problems considered include random level-shift models, outliers and missing values. Real examples are used to illustrate the analysis.     

APPLICATION OF GELATIN FOR ENCAPSULATING ASPIRIN INTO ETHYL CELLULOSE MICROCAPSULE IN AN O/W EMULSION

The application of gelatin protective colloid for microencapsulating aspirin in ethylcellulose was demonstrated using an oil-in-water emulsification/solvent evaporation technique. The gelatin concentration, alcohol co-solvent amount, and ethylcellulose viscosity were investigated by analyzing the recovered weight, particle size distribution, drug loading efficiency, aspirin release rate, surface characteristics, and release kinetics. Results showed that recovery increased with greater concentrations of gelatin (up to 1%). Adding co-solvent (ethanol) also changed the microcapsule particle size distribution. Higher recovery and release rates were obtained when the ethanol content in polymer solvent was at 25% and the viscosity of ethylcellulose was low (45cps). The release rate followed Higuchi matrix release kinetics, suggesting a monolithic system with aspirin uniformly distributed over the microcapsule.     

Integrating process and power grid models for optimal design and demand response operation of giga-scale green hydrogen

Electrolysis-based hydrogen production can play a significant role in industrial decarbonization, and its economic competitiveness can be promoted by designing demand response operating schemes. Nevertheless, the scale of industrial supply plants may be significantly large (on the order of gigawatts), meaning that electricity prices cannot be treated as an input for scheduling problems, that is, the “price taker” approach. This article presents a framework for the optimization of a large-scale, electricity-powered hydrogen production facility considering its integration with the power grid. Using a computational case study, we present an iterative scheme for integrating the process model with a model for power grid optimization and capacity expansion, taking the popular GenX model as an example.