Showing papers by "City University of Hong Kong published in 2009"
01 Dec 2009
TL;DR: An adaptive particle swarm optimization that features better search efficiency than classical particle Swarm optimization (PSO) is presented and can perform a global search over the entire search space with faster convergence speed.
Abstract: An adaptive particle swarm optimization (APSO) that features better search efficiency than classical particle swarm optimization (PSO) is presented. More importantly, it can perform a global search over the entire search space with faster convergence speed. The APSO consists of two main steps. First, by evaluating the population distribution and particle fitness, a real-time evolutionary state estimation procedure is performed to identify one of the following four defined evolutionary states, including exploration, exploitation, convergence, and jumping out in each generation. It enables the automatic control of inertia weight, acceleration coefficients, and other algorithmic parameters at run time to improve the search efficiency and convergence speed. Then, an elitist learning strategy is performed when the evolutionary state is classified as convergence state. The strategy will act on the globally best particle to jump out of the likely local optima. The APSO has comprehensively been evaluated on 12 unimodal and multimodal benchmark functions. The effects of parameter adaptation and elitist learning will be studied. Results show that APSO substantially enhances the performance of the PSO paradigm in terms of convergence speed, global optimality, solution accuracy, and algorithm reliability. As APSO introduces two new parameters to the PSO paradigm only, it does not introduce an additional design or implementation complexity.
1,713 citations
Abstract: This article presents an overview of the developments in stainless steels made since the 1990s. Some of the new applications that involve the use of stainless steel are also introduced. A brief introduction to the various classes of stainless steels, their precipitate phases and the status quo of their production around the globe is given first. The advances in a variety of subject areas that have been made recently will then be presented. These recent advances include (1) new findings on the various precipitate phases (the new J phase, new orientation relationships, new phase diagram for the Fe–Cr system, etc.); (2) new suggestions for the prevention/mitigation of the different problems and new methods for their detection/measurement and (3) new techniques for surface/bulk property enhancement (such as laser shot peening, grain boundary engineering and grain refinement). Recent developments in topics like phase prediction, stacking fault energy, superplasticity, metadynamic recrystallisation and the calculation of mechanical properties are introduced, too. In the end of this article, several new applications that involve the use of stainless steels are presented. Some of these are the use of austenitic stainless steels for signature authentication (magnetic recording), the utilisation of the cryogenic magnetic transition of the sigma phase for hot spot detection (the Sigmaplugs), the new Pt-enhanced radiopaque stainless steel (PERSS) coronary stents and stainless steel stents that may be used for magnetic drug targeting. Besides recent developments in conventional stainless steels, those in the high-nitrogen, low-Ni (or Ni-free) varieties are also introduced. These recent developments include new methods for attaining very high nitrogen contents, new guidelines for alloy design, the merits/demerits associated with high nitrogen contents, etc.
1,668 citations
TL;DR: A survey of users of an on-line consumer discussion forum in China substantiated the effects of the determinants, although post-hoc analyses revealed that prior knowledge and involvement level moderate some of them.
Abstract: Word-of-mouth (WOM) study is extended to the on-line context (eWOM) by examining the informational and normative determinants of the perceived credibility of on-line consumer recommendations. A survey of users of an on-line consumer discussion forum in China substantiated the effects of the determinants, although post-hoc analyses revealed that prior knowledge and involvement level moderate some of them. Implications for research and practice are discussed.
1,032 citations
TL;DR: Surprisingly, it is found that a network under a typical framework can realize synchronization subject to any linear feedback pinning scheme by using adaptive tuning of the coupling strength.
962 citations
TL;DR: A number of approaches have been proposed for rendering the implant surface antibacterial by impeding the formation of a biofilm and they are reviewed in this article.
Abstract: Titanium and titanium alloys are key biomedical materials because of their good biocompatibility and mechanical properties. Nevertheless, infection on and around titanium implants still remains a problem which is usually difficult to treat and may lead to eventual implant removal. As a result, preventive measures are necessary to mitigate implant-frelated infection. One important strategy is to render the implant surface antibacterial by impeding the formation of a biofilm. A number of approaches have been proposed for this purpose and they are reviewed in this article. ' 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 91B: 470-480, 2009
776 citations
Posted Content•
TL;DR: In this paper, the authors investigated the effects of largest-shareholder ownership concentration, foreign ownership, and audit quality on the amount of firm-specific information incorporated into share prices, as measured by stock price synchronicity, of Chinese-listed firms over the 1996-2003 period.
Abstract: This paper investigates the effects of largest-shareholder ownership concentration, foreign ownership, and audit quality on the amount of firm-specific information incorporated into share prices, as measured by stock price synchronicity, of Chinese-listed firms over the 1996-2003 period. We show that synchronicity is a concave function of ownership by the largest shareholder with its maximum at an approximately 50% level. Further, we find that synchronicity is higher when the largest shareholder is government related. We also find that foreign ownership and auditor quality are inversely associated with synchronicity. Finally, we show that the amount of earnings information reflected in stock returns is lower for firms with high synchronicity.
725 citations
TL;DR: In this article, independent corporate boards of Hong Kong firms provide effective monitoring of earnings management, which suggests that despite differences in institutional environments, corporate board independence is important to ensure high-quality financial reporting.
545 citations
TL;DR: F fuzzy risk priority numbers (FRPNs) are proposed for prioritization of failure modes, defined as fuzzy weighted geometric means of the fuzzy ratings for O, S and D, and can be computed using alpha-level sets and linear programming models.
Abstract: Failure mode and effects analysis (FMEA) has been extensively used for examining potential failures in products, processes, designs and services. An important issue of FMEA is the determination of risk priorities of the failure modes that have been identified. The traditional FMEA determines the risk priorities of failure modes using the so-called risk priority numbers (RPNs), which require the risk factors like the occurrence (O), severity (S) and detection (D) of each failure mode to be precisely evaluated. This may not be realistic in real applications. In this paper we treat the risk factors O, S and D as fuzzy variables and evaluate them using fuzzy linguistic terms and fuzzy ratings. As a result, fuzzy risk priority numbers (FRPNs) are proposed for prioritization of failure modes. The FRPNs are defined as fuzzy weighted geometric means of the fuzzy ratings for O, S and D, and can be computed using alpha-level sets and linear programming models. For ranking purpose, the FRPNs are defuzzified using centroid defuzzification method, in which a new centroid defuzzification formula based on alpha-level sets is derived. A numerical example is provided to illustrate the potential applications of the proposed fuzzy FMEA and the detailed computational process of the FRPNs.
539 citations
TL;DR: The complexity of finding a Nash equilibrium in a two-player game is complete for the complexity class PPAD (Polynomial Parity Argument, Directed version) introduced by Papadimitriou in 1991 as discussed by the authors.
Abstract: We prove that Bimatrix, the problem of finding a Nash equilibrium in a two-player game, is complete for the complexity class PPAD (Polynomial Parity Argument, Directed version) introduced by Papadimitriou in 1991.Our result, building upon the work of Daskalakis et al. [2006a] on the complexity of four-player Nash equilibria, settles a long standing open problem in algorithmic game theory. It also serves as a starting point for a series of results concerning the complexity of two-player Nash equilibria. In particular, we prove the following theorems:—Bimatrix does not have a fully polynomial-time approximation scheme unless every problem in PPAD is solvable in polynomial time.—The smoothed complexity of the classic Lemke-Howson algorithm and, in fact, of any algorithm for Bimatrix is not polynomial unless every problem in PPAD is solvable in randomized polynomial time.Our results also have a complexity implication in mathematical economics:—Arrow-Debreu market equilibria are PPAD-hard to compute.
497 citations
TL;DR: In this article, the authors combine and explore two new data sources, an original cross-national data set on particular types of decentralization and the results of a firm level survey conducted in 80 countries about firms' concrete experiences with bribery.
482 citations
TL;DR: A systematic literature review was performed to identify variables promoting consumer health information technology (CHIT) acceptance among patients to improve understanding of patient CHIT acceptance, which could lead to better CHIT design and implementation.
TL;DR: In this paper, the authors investigate whether and how the size of a local practice office within an audit firm (henceforth, office size) is a significant, engagement-specific factor determining audit quality and audit fees over and beyond audit firm size at the national level and auditor industry leadership at the city or office level.
Abstract: Using a large sample of U.S. audit client firms over the period 2000-2005, this paper investigates whether and how the size of a local practice office within an audit firm (henceforth, office size) is a significant, engagement-specific factor determining audit quality and audit fees over and beyond audit firm size at the national level and auditor industry leadership at the city or office level. For our empirical tests, audit quality is measured by unsigned abnormal accruals, and the office size is measured in two different ways: one based on the number of audit clients in each office and the other based on a total of audit fees earned by each office. Our results show that the office size has significantly positive relations with both audit quality and audit fees even after controlling for national-level audit firm size and office-level industry expertise. These positive relations support the view that large local offices provide higher-quality audits, compared with small local offices and that such quality differences are priced in the market for audit services.
TL;DR: In this paper, a study of the appropriateness of glass cover on a thermosyphon-based water-heating photovoltaic-thermal (PV/T) system was carried out.
01 Mar 2009
TL;DR: It is proposed that knowledge management system (KMS) users' beliefs are contextually differentiated, and thus a distinction between knowledge-contribution and knowledge-seeking behaviors and an adequate emphasis on their variance in terms of user belief is needed.
Abstract: Knowledge management (KM) research has yielded extensive explanations regarding the individual's motivation to share knowledge, each with different sets of factors. Yet the study of continued knowledge sharing is rare. There has been little research investigating this issue from contributing and seeking perspectives-the two distinct, but closely interrelated, facets of continued knowledge sharing. We propose that knowledge management system (KMS) users' beliefs are contextually differentiated, and thus a distinction between knowledge-contribution and knowledge-seeking behaviors and an adequate emphasis on their variance in terms of user belief is needed. By incorporating the knowledge-contribution and knowledge-seeking perspectives in a single study, we model and examine the differences among driving factors in two behavioral contexts, provide the conceptual comparisons and preliminary discussions, and thus advance our understanding of continued knowledge sharing via the KMS.
01 Sep 2009
TL;DR: This work analyzes Poisson regression in a Bayesian setting, by introducing a prior distribution on the weights of the linear function, and shows that the predictive distribution can be kernelized, enabling the representation of non-linear log-mean functions.
Abstract: Poisson regression models the noisy output of a counting function as a Poisson random variable, with a log-mean parameter that is a linear function of the input vector In this work, we analyze Poisson regression in a Bayesian setting, by introducing a prior distribution on the weights of the linear function Since exact inference is analytically unobtainable, we derive a closed-form approximation to the predictive distribution of the model We show that the predictive distribution can be kernelized, enabling the representation of non-linear log-mean functions We also derive an approximate marginal likelihood that can be optimized to learn the hyperparameters of the kernel We then relate the proposed approximate Bayesian Poisson regression to Gaussian processes Finally, we present experimental results using Bayesian Poisson regression for crowd counting from low-level features
TL;DR: In this paper, the authors examined the effect of firm-level corporate governance on the cost of equity capital in emerging markets and how the effect is influenced by country-level legal protection of investors.
TL;DR: This study finds broad support for the proposed analytical framework for relational and contractual mechanisms in foreign subsidiaries' acquisition of tacit and explicit knowledge from local suppliers in China and provides important implications for foreign subsidiaries regarding how to acquire local knowledge in host countries through both formal and informal mechanisms.
Abstract: This research focuses on relational and contractual mechanisms and examines their impact on foreign subsidiaries' acquisition of tacit and explicit knowledge from local suppliers. Using survey data from 168 foreign subsidiaries operating in China, this study finds broad support for the proposed analytical framework. When the foreign subsidiary and supplier share common goals, the foreign subsidiary acquires greater levels of both explicit and tacit knowledge; trust between the two parties promotes the acquisition of greater levels of tacit than explicit knowledge. However, access to the local supplier network through the focal supplier enables the foreign subsidiary to acquire greater levels of explicit but not tacit knowledge. Formal contracts play a complementary role in knowledge acquisition: contracts enhance the acquisition of explicit knowledge and further strengthen the effects of relational mechanisms on tacit and explicit knowledge acquisition. Overall, these findings provide important implications for foreign subsidiaries regarding how to acquire local knowledge in host countries through both formal and informal mechanisms. Copyright © 2009 John Wiley & Sons, Ltd.
01 Dec 2009
TL;DR: In this paper, a new filtering problem for sensor networks is investigated, where each sensor can communicate with the neighboring sensors, and filtering can be performed in a distributed way.
Abstract: In this paper, a new filtering problem for sensor networks is investigated. A new type of distributed consensus filters is designed, where each sensor can communicate with the neighboring sensors, and filtering can be performed in a distributed way. In the pinning control approach, only a small fraction of sensors need to measure the target information, with which the whole network can be controlled. Furthermore, pinning observers are designed in the case that the sensor can only observe partial target information. Simulation results are given to verify the designed distributed consensus filters.
TL;DR: In this article, the authors examined the effects of both borrower and lender competition as well as information sharing via credit bureaus/registries on corruption in bank lending, and found strong evidence that both banking competition and information sharing reduce lending corruption, and that information sharing also helps enhance the positive effect of competition.
TL;DR: Using the Lyapunov method and stochastic analysis techniques, sufficient conditions are first derived to guarantee the existence of the desired controllers, and then the controller parameters are characterized in terms of linear matrix inequalities (LMIs).
TL;DR: In this article, the empirical determinants of China's outward direct investment (ODI) are investigated and it is found that China's investments in developed and developing countries are driven by different sets of factors.
Abstract: We investigate the empirical determinants of China’s outward direct investment (ODI). It is found that China’s investments in developed and developing countries are driven by different sets of factors. Subject to the differences between developed and developing countries, there is evidence that a) both market seeking and resources seeking motives drive China’s ODI, b) the Chinese exports to developing countries induce China’s ODI, c) China’s international reserves promote its ODI, and d) the Chinese capital tends to agglomerate among developed economies but diversify among developing economies. Similar results are obtained using alternative ODI data. We do not find substantial evidence that China invests in African and oil-producing countries mainly for their natural resources.
TL;DR: Results from qualitative analyses revealed that initial conditions to participate did not effectively predict long-term participation, but that situated learning and identity construction behaviors were positively linked to sustained participation.
Abstract: Prior research into open source software (OSS) developer participation has emphasized individuals' motivations for joining these volunteer communities, but it has failed to explain why people stay or leave in the long run. Building upon Lave and Wenger's theory of legitimate peripheral participation (LPP), this paper offers a longitudinal investigation of one OSS community in which sustained participation is hypothesized to be associated with the coevolution of two major elements of LPP theory: "situated learning" (the process of acting knowledgeably and purposefully in the world) and "identity construction" (the process of being identified within the community). To test this hypothesis, data were collected from multiple sources, including online public project documents, electronic mail messages, tracker messages, and log files. Results from qualitative analyses revealed that initial conditions to participate did not effectively predict long-term participation, but that situated learning and identity construction behaviors were positively linked to sustained participation. Furthermore, this study reveals that sustained participants distinguished themselves by consistently engaging in situated learning that both made conceptual (advising others) and practical contributions (improving the code). Implications and future research are discussed.
TL;DR: In this paper, the authors explored the performance consequences of firms' alliance partner selection by examining the interactions of resource complementarity and institutional associations between the firm and its partners, and suggested that it is necessary to consider both societal and network status as they can have distinct effects under certain conditions.
Abstract: Bridging the resource-based view and the institutional perspective, this study explores the performance consequences of firms' alliance partner selections by examining the interactions of resource complementarity and institutional associations (reflected through both societal and network status) between the firm and its partners. The integrative framework suggests that a joint consideration of resource complementarity and status effects, as well as important firm- and environmental-level contingent factors, are critical for understanding the underlying mechanisms of alliance formations and their effects on firm performance. Further, our study suggests that it is necessary to consider both societal and network status as they can have distinct effects under certain conditions. Our analyses of four U.S. industries (computer, steel, pharmaceutics, crude petroleum and natural gas) over a span of 13 years largely support our framework. Copyright © 2009 John Wiley & Sons, Ltd.
TL;DR: It is argued that fine-tuned information transmission delays are vital for assuring optimally synchronized excitatory fronts on complex neuronal networks and, indeed, they should be seen as important as the coupling strength or the overall density of interneuronal connections.
Abstract: We investigate front propagation and synchronization transitions in dependence on the information transmission delay and coupling strength over scale-free neuronal networks with different average degrees and scaling exponents. As the underlying model of neuronal dynamics, we use the efficient Rulkov map with additive noise. We show that increasing the coupling strength enhances synchronization monotonously, whereas delay plays a more subtle role. In particular, we found that depending on the inherent oscillation frequency of individual neurons, regions of irregular and regular propagating excitatory fronts appear intermittently as the delay increases. These delay-induced synchronization transitions manifest as well-expressed minima in the measure for spatial synchrony, appearing at every multiple of the oscillation frequency. Larger coupling strengths or average degrees can broaden the region of regular propagating fronts by a given information transmission delay and further improve synchronization. These results are robust against variations in system size, intensity of additive noise, and the scaling exponent of the underlying scale-free topology. We argue that fine-tuned information transmission delays are vital for assuring optimally synchronized excitatory fronts on complex neuronal networks and, indeed, they should be seen as important as the coupling strength or the overall density of interneuronal connections. We finally discuss some biological implications of the presented results.
TL;DR: In this paper, the authors examined how Chinese state-owned banks allocate loans to private firms and found that the banks extend loans to financially healthier and better-governed firms, which implies that banks use commercial judgments in this segment of the market.
Abstract: This study examines how the Chinese state-owned banks allocate loans to private firms. We find that the banks extend loans to financially healthier and better-governed firms, which implies that the banks use commercial judgments in this segment of the market. We also find that having the state as a minority owner helps firms obtain bank loans and this suggests that political connections play a role in gaining access to bank finance. In addition, we find that commercial judgments are important determinants of the lending decisions for manufacturing firms, large firms, and firms located in regions with a more developed banking sector; political connections are important for firms in service industries, large firms, and firms located in areas with a less developed banking sector.
TL;DR: A free vibration analysis of metal and ceramic functionally graded plates that uses the element-free kp-Ritz method is presented in this paper, where the material properties of the plates are assumed to vary continuously through their thickness according to a power-law distribution of the volume fractions of the plate constituents.
TL;DR: It is shown that by using a simple linearization technique incorporating a bounding inequality, a unified framework can be developed such that both the full-order and reduced-order filters can be obtained by solving a set of linear matrix inequalities (LMIs), which are numerically efficient with commercially available software.
Abstract: This paper investigates the problem of delay-dependent robust H infin filtering design for a class of uncertain discrete-time state-delayed Takagi-Sugeno (T-S) fuzzy systems. The state delay is assumed to be time-varying and of an interval-like type, which means that both the lower and upper bounds of the time-varying delay are available. The parameter uncertainties are assumed to have a structured linear fractional form. Based on a novel fuzzy-basis-dependent Lyapunov-Krasovskii functional combined with Finsler's lemma and an improved free-weighting matrix technique for delay-dependent criteria, a new sufficient condition for robust H infin performance analysis is first derived, and then, the filter synthesis is developed. It is shown that by using a simple linearization technique incorporating a bounding inequality, a unified framework can be developed such that both the full-order and reduced-order filters can be obtained by solving a set of linear matrix inequalities (LMIs), which are numerically efficient with commercially available software. Finally, simulation examples are provided to illustrate the advantages and less conservatism of the proposed approach.
TL;DR: In this paper, the authors focused on two theoretically grounded practical web strategies of customer endorsement and portal affiliation, and compared them across two research sites: Australia (individualistic culture) and Hong Kong (collectivistic culture).
Abstract: Building consumer trust is important for new or unknown Internet businesses seeking to extend their customer reach globally. This study explores the question: Should website designers take into account the cultural characteristics of prospective customers to increase trust, given that different trust-building web strategies have different cost implications? In this study, we focused on two theoretically grounded practical web strategies of customer endorsement, which evokes unit grouping, and portal affiliation, which evokes reputation categorization, and compared them across two research sites: Australia (individualistic culture) and Hong Kong (collectivistic culture). The results of the laboratory experiment we conducted, on the website of an online bookstore, revealed that the impact of peer customer endorsements on trust perceptions was stronger for subjects in Hong Kong than Australia and that portal (Yahoo) affiliation was effective only in the Australian site. A follow-up study was conducted as a conceptual replication, and provided additional insights on the effects of customer endorsement versus firm affiliation on trust-building. Together, these findings highlight the need to consider cultural differences when identifying the mix of web strategies to employ in Internet store websites.
TL;DR: Wang et al. as discussed by the authors examined the relationship between proactive personality, employee creativity, and newcomer outcomes (i.e., career satisfaction and perceived insider status) and found that proactive personality was positively associated with employee creativity and employee creativity was associated with career satisfaction.
Abstract: Purpose To examine the relationship between proactive personality, employee creativity, and newcomer outcomes (i.e., career satisfaction and perceived insider status). Design/methodology/approach A survey was conducted using a 3-wave longitudinal design with 146 Hong Kong Chinese employees from various organizations. Structural equation modeling was used to test the research hypotheses including the mediation effects. Findings Proactive personality was positively associated with employee creativity and employee creativity was positively associated with career satisfaction and perceived insider status. In addition, employee creativity fully mediated the relationships between proactive personality and career satisfaction and perceived insider status. Implications Based on self-reported responses, these data show that newcomers with a proactive personality shape their work environments in part through creative behavior, which in turn leads to feelings of career satisfaction and perceptions of being an organizational insider. Our study’s results also show that employee creativity is positively and significantly related to workers’ career satisfaction and perceived insider status, suggesting that employee creativity can improve employees’ attitudes toward their career and perceptions as valued and contributing organizational insiders. Future research may examine other possible variables that might mediate the relationship between proactive personality and individual outcomes. Originality/value One of the few studies that have examined the intervening mechanism by which proactive personality leads to employee outcomes and examined the effects of proactive personality on employee outcomes in Asian culture.
TL;DR: The aim is to develop a robust fault detection approach to the T-S fuzzy systems with Brownian motion by using a general observer-based fault detection filter as a residual generator, and attention is focused on the design of both the fuzzy-rule-independent and the fuzzy -rule-dependent fault detection filters guaranteeing a prescribed noise attenuation level in an Hinfin sense.
Abstract: The paper deals with the robust fault detection problem for Takagi-Sugeno (T-S) fuzzy Ito stochastic systems. Our aim is to develop a robust fault detection approach to the T-S fuzzy systems with Brownian motion. By using a general observer-based fault detection filter as a residual generator, the robust fault detection is formulated as a filtering problem. Attention is focused on the design of both the fuzzy-rule-independent and the fuzzy-rule-dependent fault detection filters guaranteeing a prescribed noise attenuation level in an Hinfin sense. Sufficient conditions are proposed to guarantee the mean-square asymptotic stability with an Hinfin performance for the fault detection system. The corresponding solvability conditions for the desired fuzzy-rule-independent and fuzzy-rule-dependent fault detection filters are also established. Finally, a numerical example is provided to illustrate the effectiveness of the proposed theory.