Showing papers by "City University of Hong Kong published in 2000"

Microstructural and mechanical characteristics of in situ metal matrix composites

Abstract: During the past decade, considerable research effort has been directed towards the development of in situ metal matrix composites (MMCs), in which the reinforcements are formed in situ by exothermal reactions between elements or between elements and compounds. Using this approach, MMCs with a wide range of matrix materials (including aluminum, titanium, copper, nickel and iron), and second-phase particles (including borides, carbides, nitrides, oxides and their mixtures) have been produced. Because of the formation of ultrafine and stable ceramic reinforcements, the in situ MMCs are found to exhibit excellent mechanical properties. In this review article, current development on the fabrication, microstructure and mechanical properties of the composites reinforced with in situ ceramic phases will be addressed. Particular attention is paid to the mechanisms responsible for the formation of in situ reinforcements, and for creep failure of the aluminum-based matrix composites.

Learning from Adopters’ Experiences with ERP: Problems Encountered and Success Achieved:

Abstract: Enterprise resource planning (ERP) packages touch many aspects of a company's internal and external operations. Consequently, successful deployment and use of ERP systems are critical to organizational performance and survival. This paper presents the results of a study of the problems and outcomes in ERP projects which was conducted under the sponsorship of an ERP systems vendor. Two basic research questions were addressed. First, how successful are companies at different points in time in their ERP experiences and how are different measures of success related? (That is, can early success be followed by failure and vice versa?) Second, what problems do ERP adopters encounter as they implement and deploy ERP and how are these problems related to outcomes? The findings showed that the success of ERP systems depends on when it is measured and that success at one point in time may only be loosely related to success at another point in time. Companies experience problems at all phases of the ERP system life cycle and many of the problems experienced in later phases originated earlier but remained unnoticed or uncorrected. These findings suggest that researchers and companies will do well to adopt broad definitions and multiple measures of success and pay particular attention to the early identification and correction of problems.

Productivist Welfare Capitalism: Social Policy in East Asia:

Abstract: The article engages with the literature on the ‘East Asian welfare model’ by using Esping-Andersen's ‘worlds of welfare capitalism’ approach to analyze social policy in the region. It describes the main features of a productivist world of welfare capitalism that stands alongside Esping-Andersen's conservative, liberal and social democratic worlds. It then shows that Japan, Hong Kong, Singapore, South Korea and Taiwan are all part of this world, though they divide into sub-groups within it. To account for productivist welfare capitalism in East Asia, the article focuses particularly on bureaucratic politics at the unit level, and on a range of key shaping factors at the system level. It closes by considering the implications of East Asian experience for comparative social policy analysis.

What makes consumers buy from Internet? A longitudinal study of online shopping

Abstract: The objective of this study is to investigate the factors affecting online shopping. A model explaining the impact of different factors on online shopping intentions and behavior is developed based on the theory of planned behavior. The model is then tested empirically in a longitudinal study with two surveys. Data collected from 705 consumers indicate that subjective norms, attitude, and beliefs concerning the consequences of online shopping have significant effects on consumers' intentions to buy online. Behavioral control and intentions significantly influenced online shopping behavior. The results also provide strong support for the positive effects of personal innovativeness on attitude and intentions to shop online. The implications of the findings for theory and practice are discussed.

Assessing Extreme and Acquiescence Response Sets in Cross-Cultural Research Using Structural Equations Modeling

Abstract: Extreme response styles (ERS) and acquiescence response styles (ARS) may constitute important sources of cross-cultural differences on survey-type instruments. Differences in ERS and ARS, if undetected, may give rise to spurious results that do not reflect genuine differences in attitudes or perceptions. Multiple-group confirmatory factor analysis is recommended as the most effective method of testing for ERS and ARS and determining whether cultural groups can be meaningfully compared on the basis of factor (latent) means. A detailed numerical example is provided.

Introduction to Fuzzy Sets, Fuzzy Logic, and Fuzzy Control Systems

Abstract: FUZZY SET THEORY Classical Set Theory Fuzzy Set Theory Interval Arithmetic Operations on Fuzzy Sets FUZZY LOGIC THEORY Classical Logic Theory The Boolean Algebra Multi-Valued Logic Fuzzy Logic and Approximate Reasoning Fuzzy Relations Fuzzy Logic Rule Base FUZZY SYSTEM MODELING Modeling of the Static Fuzzy Systems Stability Analysis of Discrete-Time Dynamic Fuzzy Systems Modeling of Continuous-Time Dynamic Fuzzy Systems Stability Analysis of Continuous-Time Fuzzy Systems Controllability Analysis of Continuous-Time Dynamic Fuzzy Systems Analysis of Nonlinear Continuous-Time Dynamic Fuzzy Systems FUZZY CONTROL SYSTEMS Classical Programmable Logic Control Fuzzy Logic Control I: A General Model-Free Approach Fuzzy Logic Control II: A General Model-Based Approach FUZZY PID CONTROLLERS Conventional PID Controllers Fuzzy PID Controllers Fuzzy PID Controllers: Stability Analysis ADAPTIVE FUZZY CONTROL Fundamental Adaptive Fuzzy Control Concept Gain Scheduling Fuzzy Self-Tuning Regulator Model Reference Adaptive Fuzzy Systems Dual Control Sub-Optimal Fuzzy Control APPLICATIONS IN FUZZY CONTROL Health Monitoring Fuzzy Diagnostic Systems Fuzzy Control of Image sharpness for Auto-focus Cameras Fuzzy Control for Servo Mechanic Systems Fuzzy PID Controllers for Servo Mechanic Systems Fuzzy Controllers for Robotic Manipulator Note: Each chapter also contains Problems and References

Circumventing the ill-conditioning problem with multiquadric radial basis functions: Applications to elliptic partial differential equations

Abstract: Madych and Nelson [1] proved multiquadric (MQ) mesh-independent radial basis functions (RBFs) enjoy exponential convergence. The primary disadvantage of the MQ scheme is that it is global, hence, the coefficient matrices obtained from this discretization scheme are full. Full matrices tend to become progressively more ill-conditioned as the rank increases. In this paper, we explore several techniques, each of which improves the conditioning of the coefficient matrix and the solution accuracy. The methods that were investigated are 1. (1) replacement of global solvers by block partitioning, LU decomposition schemes, 2. (2) matrix preconditioners, 3. (3) variable MQ shape parameters based upon the local radius of curvature of the function being solved, 4. (4) a truncated MQ basis function having a finite, rather than a full band-width, 5. (5) multizone methods for large simulation problems, and 6. (6) knot adaptivity that minimizes the total number of knots required in a simulation problem. The hybrid combination of these methods contribute to very accurate solutions. Even though FEM gives rise to sparse coefficient matrices, these matrices in practice can become very ill-conditioned. We recommend using what has been learned from the FEM practitioners and combining their methods with what has been learned in RBF simulations to form a flexible, hybrid approach to solve complex multidimensional problems.

Tropical Cyclone Activity over the Western North Pacific Associated with El Niño and La Niña Events

Abstract: This paper presents the results of an investigation on the variations of tropical cyclone (TC) activity over the western North Pacific (WNP) associated with both El Nino (EN) and La Nina (LN) events. The study is based on the monthly number of TCs that occurred during the period 1959–97. Anomalies within each 5° lat × 5° long box from the year before (EN−1 and LN−1) to the year after (EN+1 and LN+1) are examined. During an EN−1 year, more (less) TCs are found in September and October over the South China Sea (southeast of Japan). In an EN year, TC activity is below normal during these two months over the South China Sea (SCS) but above normal especially in the late season in the eastern part of the WNP. After the mature phase of the warm event (i.e., during an EN+1 year), TC activity over the entire ocean basin tends to be below normal. No significant anomalies are found during an LN−1 year. However, in an LN year, the SCS tends to have more TCs in September and October, but for the rest of the W...

Drift-independent volatility estimation based on high, low, open, and close prices

Abstract: We present a new volatility estimator based on multiple periods of high, low, open, and close prices in a historical time series. The new estimator has the following nice properties: it is (a) unbiased in the continuous limit, (b) independent of the drift, (c) consistent in dealing with opening price jumps. Furthermore, it has the smallest variance among all estimators with similar properties. The improvement of accuracy over the classical close-to-close estimator is dramatic for real-life time series. Copyright 2000 by University of Chicago Press.

Discourse Community, Legitimate Peripheral Participation, and the Nonnative-English-Speaking Scholar.

Abstract: This article presents a case study of a nonnative-English-speaking scholar from Hong Kong and his experience in publishing a scholarly article in an international refereed journal on his return from doctoral study in the United States. The investigation is presented as a contribution to the important study of what it means to be a non-anglophone researcher seeking international publication in English but living and researching in a non-anglophone country. The article applies elements of social constructivist theory—most importantly the notions of discourse community (e.g., Swales, 1990) and learning as peripheral participation (Lave & Wenger, 1991)—to interpret the difficulties the writer experiences. It also considers the role that TESOL may play in addressing these difficulties.

Experimental study of a microstrip patch antenna with an L-shaped probe

Abstract: The L-shaped probe is shown to be an attractive feed for the thick microstrip antenna (thickness around 10% of the operating wavelength). A parametric study on the rectangular patch antenna is presented. It is found that the antenna attains 36% impedance bandwidth (SWR/spl les/2) as well as gain bandwidth and about 7-dBi average gain. A two-element array fed by L-probes is also proposed. Experiments show that the array design can substantially suppress the cross polarization of the proposed antenna. Both the antennas have stable radiation patterns across the passband. Moreover, the measured resonant frequencies of the proposed antenna agree well with an existing formula and the L-probe does not have much effect on the resonant frequency.

Methodological Issues in Psychological Research on Culture

Abstract: The extent to which methodological tools can help correct the overemphasis on fact finding and speed up the slow theoretical progress in cross-cultural psychology is analyzed. Two types of contributions to the current predicament are delineated. First, cross-cultural psychologists have created their own partis pris. Second, partis pris have been inherited from mainstream psychology. In the future, most cross-cultural studies will be carried out by researchers who have an interest in cultural variations on specific variables or instruments, whereas the group of researchers who spend their professional lives in cross-cultural psychology will remain small but influential. Methodological issues arising in studies by both groups are described. Important trends are (a) the change from exploration to explanation of cross-cultural differences, which has implications for the design of cross-cultural studies; and (b) the so-far-hesitant usage of recently developed statistical techniques, such as item response theor...

Tone Sandhi: Patterns across Chinese Dialects

Abstract: Preface Notational conventions 1 Setting the stage 2 Tonal representation and tonal processes 3 Directionality and interacting sandhi processes I 4 Directionality and interacting sandhi processes II 5 From base tones to sandhi forms: a constraint-based analysis 6 From tone to accent 7 Stress-foot as sandhi domain I 8 Stress-foot as sandhi domain II 9 Minimal rhythmic unit as obligatory sandhi domain 10 Phonological phrase as a sandhi domain 11 From tone to intonation Concluding remarks Bibliographical appendix: tone sandhi across Chinese dialects References Subject index Author index

Rubber toughening in polypropylene: A review

Abstract: The recent advances in the studies of the toughening methods and theories of polypropylene (PP)–elastomer blends are reviewed in the present article. Inclusions are key to toughening PP; they can play the role of agent-induced crazing, cause shear yielding of the matrix around them, and end the propagation of cracks. The major theories interpreting the toughening mechanisms of the blends are: multiple crazing, damage competition theory, shear-yielding theory, microvoids, and cavitation theories. The factors affecting the toughening effect are relatively complicated. Therefore, these theories have been verified only in some cases when they have been applied in relevant conditions. To achieve the objective of better toughening, it is important to improve the uniform distribution of dispersed-phase particle size and suitable filler size, as well as improving the dispersion of the inclusions formed in the matrix; in addition the matrix materials or fillers must be functional with suitable modifier in order to enhance the interfacial adhesion or to improve the interfacial morphological structure between the filler and matrix. However, the exact toughening mechanisms for PP–rubber blends have to be studied further because of complications resulting from the crystallinity of the matrix. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 409–417, 2000

An exploratory cross-sectional study of interlanguage pragmatic development

Abstract: This paper reports the results of an exploratory cross-sectional study of pragmatic development among three groups of primary school students in Hong Kong who completed a cartoon oral production task (COPT) designed to elicit requests, apologies, and compliment responses. The first two of these speech acts are among the most well represented in the pragmatics literature and are also included in the Hong Kong English language syllabus for primary schools. The latter has also been studied extensively but is not part of the syllabus. Data was collected in Cantonese using the same instrument. Although a number of developmental patterns are revealed—particularly in choice of request strategy, frequency of supportive moves, and use of adjuncts with apologies and compliment responses—there is little evidence of sensitivity to situational variation or pragmatic transfer from Cantonese. This study adds to the small, but growing, body of research on pragmatic development in a second language.

The effect of multimedia on perceived equivocality and perceived usefulness of information systems

Abstract: With the advent of multimedia and intranet technologies, managers and information systems designers face a new challenge: how to capture and present information using a variety of representation formats (text, graphics, audio, video, and animations) so that members of an organization can make better sense out of the information available. In this study, we develop a task-representation fit model to generate several predictions about the potential of multimedia to alleviate the limitations of text-based information in the context of individual decision makers utilizing organizational data and test them in a laboratory experiment. Results support the task-representation fit relationships predicted. For analyzable tasks, text-based representation and multimedia representation are equally effective in reducing perceived equivocality levels. For less-analyzable tasks, only multimedia representation was instrumental in reducing perceived equivocality levels.

A broad-band U-slot rectangular patch antenna on a microwave substrate

Abstract: A broad-band U-slot rectangular patch antenna printed on a microwave substrate is investigated. The dielectric constant of the substrate is 2.33. The antenna is fed by a coaxial probe. The characteristics of the U-slot patch antenna are analyzed by the finite-difference time-domain (FDTD) method. Experimental results for the input impedance and radiation patterns are obtained and compared with numerical results. The maximum impedance bandwidth achieved is 27%, centered around 3.1 GHz, with good pattern characteristics.

Toxicology and risk assessment of freshwater cyanobacterial (blue-green algal) toxins in water.

Abstract: The adverse effects of cyanobacterial toxins were first reported as stock deaths at Lake Alexandrina, South Australia, in 1878. Since then, cyanobacterial poisonings in animals and humans have been widely reported around the world (Codd and Poon 1988). In fact, cattle and wildlife mortality from cyanobacterial poisonings is relatively common in many countries (Carmichael 1981). Animals that have been killed in large numbers include cattle, sheep, pigs, birds, and fish; small numbers of deaths of horses, dogs, rodents, amphibians, and invertebrates have also been recorded (Codd and Poon 1988). According to the compilations of Carmichael (1992a), approximately 85 animal poisoning incidents related to cyanobacterial blooms have been recorded around the world from 1878 to 1991.

Total quality management, ISO 9000 certification and performance improvement

Abstract: Records the research on the relationship between TQM, ISO 9000 certification and business performance improvement. The research is based on a survey conducted in Norway. Finds that the TQM criteria (or enablers) such as quality leadership, human resource development, quality information, etc. contribute to the improvement of customer satisfaction and business performance. However, none of these TQM enablers can guarantee enhanced performance. It is these enablers as a whole that contribute collectively to the improvement of performance. The study also finds that ISO 9000 standards are partially related to the implementation of TQM and the improvement of business performance. The recommendation is that ISO 9000 should be incorporated with the philosophy and methods of TQM.

Novel 1-D microstrip PBG cells

Abstract: Novel one-dimensional (1-D) microstrip photonic bandgap (PBG) cells are proposed. They are sections of microstrip line with special perforation patterns etched on the line itself. As examples, two types of PBG cell are investigated. Simulation and experiments show that the cell exhibits remarkable slow-wave and band-stop effects. An equivalent L-C circuit is used to model the PBG cell. Several cells connected in series form an excellent band-stop filter.

A compression algorithm for DNA sequences and its applications in genome comparison

Abstract: We present a lossless compression algorithm, Gen-Compress, for DNA sequences, based on searching for approximate repeats. Our algorithm achieves the best compression ratios for benchmark DNA sequences, comparing to other DNA compression programs [3, 7]. Significantly better compression results show that the approximate repeats are one of the main hidden regularities in DNA sequences.We then describe a theory of measuring the relatedness between two DNA sequences. We propose to use d(x, y) = 1 — K(x) - K(x|y)/K(xy to measure the distance of any two sequences, where K stands for Kolmogorov complexity [5]. Here, K(x) - K(x|y) is the mutual information shared by x and y. But mutual information is not a distance, there is no triangle inequality. The distance d(x, y) is symmetric. It also satisfies the triangle inequality, and furthermore, it is universal [4].It has not escaped our notice that the distance measure we have postulated can be immediately used to construct evolutionary trees from DNA sequences, especially those that cannot be aligned, such as complete genomes. With more and more genomes sequenced, constructing trees from genomes becomes possible [1, 2, 6, 8]. Kolmogorov complexity is not computable. We use GenCompress to approximate it. We present strong experimental support for this theory, and demonstrate its applicability by correctly constructing a 16S (18S) rRNA tree, and a whole genome tree for several species of bacteria. Larger scale experiments are underway at the University of Waterloo, with very promising results.