Showing papers by "University of Macau published in 2013"

Extreme Learning Machine

Abstract: This special issue includes eight original works that detail the further developments of ELMs in theories, applications, and hardware implementation. In "Representational Learning with ELMs for Big Data," Liyanaarachchi Lekamalage Chamara Kasun, Hongming Zhou, Guang-Bin Huang, and Chi Man Vong propose using the ELM as an auto-encoder for learning feature representations using singular values. In "A Secure and Practical Mechanism for Outsourcing ELMs in Cloud Computing," Jiarun Lin, Jianping Yin, Zhiping Cai, Qiang Liu, Kuan Li, and Victor C.M. Leung propose a method for handling large data applications by outsourcing to the cloud that would dramatically reduce ELM training time. In "ELM-Guided Memetic Computation for Vehicle Routing," Liang Feng, Yew-Soon Ong, and Meng-Hiot Lim consider the ELM as an engine for automating the encapsulation of knowledge memes from past problem-solving experiences. In "ELMVIS: A Nonlinear Visualization Technique Using Random Permutations and ELMs," Anton Akusok, Amaury Lendasse, Rui Nian, and Yoan Miche propose an ELM method for data visualization based on random permutations to map original data and their corresponding visualization points. In "Combining ELMs with Random Projections," Paolo Gastaldo, Rodolfo Zunino, Erik Cambria, and Sergio Decherchi analyze the relationships between ELM feature-mapping schemas and the paradigm of random projections. In "Reduced ELMs for Causal Relation Extraction from Unstructured Text," Xuefeng Yang and Kezhi Mao propose combining ELMs with neuron selection to optimize the neural network architecture and improve the ELM ensemble's computational efficiency. In "A System for Signature Verification Based on Horizontal and Vertical Components in Hand Gestures," Beom-Seok Oh, Jehyoung Jeon, Kar-Ann Toh, Andrew Beng Jin Teoh, and Jaihie Kim propose a novel paradigm for hand signature biometry for touchless applications without the need for handheld devices. Finally, in "An Adaptive and Iterative Online Sequential ELM-Based Multi-Degree-of-Freedom Gesture Recognition System," Hanchao Yu, Yiqiang Chen, Junfa Liu, and Guang-Bin Huang propose an online sequential ELM-based efficient gesture recognition algorithm for touchless human-machine interaction.

Bioactive Luminescent Transition‐Metal Complexes for Biomedical Applications

Abstract: The serendipitous discovery of the anticancer drug cisplatin cemented medicinal inorganic chemistry as an independent discipline in the 1960s. Luminescent metal complexes have subsequently been widely applied for sensing, bio-imaging, and in organic light-emitting diode applications. Transition-metal complexes possess a variety of advantages that make them suitable as therapeutics and as luminescent probes for biomolecules. It is thus highly desirable to develop new luminescent metal complexes that either interact with DNA through different binding modes or target alternative cellular machinery such as proteins as well as to provide a more effective means of monitoring disease progression. In this Review, we highlight recent examples of biologically active luminescent metal complexes that can target and probe a specific biomolecule, and offer insights into the future potential of these compounds for the investigation and treatment of human diseases.

Adaptive Fuzzy Control via Observer Design for Uncertain Nonlinear Systems With Unmodeled Dynamics

Abstract: In this paper, the problems of stability and tracking control for a class of large-scale nonlinear systems with unmodeled dynamics are addressed by designing the decentralized adaptive fuzzy output feedback approach. Because the dynamic surface control technique is introduced, the designed controllers can avoid the issue of “explosion of complexity,” which comes from the traditional backstepping design procedure that deals with large-scale nonlinear systems with unmodeled dynamics. In addition, a reduced-order observer is designed to estimate those immeasurable states. Based on the Lyapunov stability method, it is proven that all the signals in the closed-loop system are bounded, and the system outputs track the reference signals to a small neighborhood of the origin by choosing the design parameters appropriately. The simulation examples are given to verify the effectiveness of the proposed techniques.

Cultural meaning of perceived control: A meta-analysis of locus of control and psychological symptoms across 18 cultural regions.

Abstract: Integrating more than 40 years of studies on locus of control (LOC), this meta-analysis investigated whether (a) the magnitude of the relationship between LOC and psychological symptoms differed among cultures with distinct individualist orientations and (b) depression and anxiety symptoms yielded different patterns of cultural findings with LOC. We included studies that examined global self-ratings of LOC and at least 1 of the criterion variables in nonclinical samples (age range: 18-80 years). Data were analyzed on the basis of 152 independent samples, representing the testing of 33,224 adults across 18 cultural regions. Results revealed moderately strong relationships for external LOC with depression symptoms (k = 123, N = 28,490, r = .30, 95% confidence interval [CI] [.27, .32]) and anxiety symptoms (k = 65, N = 13,208, r = .30, 95% CI [.27, .33]). Individualism explained 20% of unique variance only in the external LOC-anxiety relationship: The link between external LOC and anxiety symptoms was weaker for collectivist societies (k = 8, N = 2,297, r = .20, 95% CI [.13, .28]) compared with individualist societies (k = 54, N = 9,887, r = .32, 95% CI [.29, .34]). Such cultural differences were attributed to the reduced emphasis on agentic goals in more collectivist societies. It is noteworthy that external LOC does not carry the same negative connotations across cultures, and members of collectivist societies may be more ready to endorse such items. Culture has been examined at the country level, and the findings may not be applicable to any particular person in a cultural region. Implications for integrating cultural meaning of perceived control into formulation of theories, research design, and intervention programs are discussed.

Psychological risk factors of addiction to social networking sites among Chinese smartphone users.

Abstract: Background and aims Smartphones allow users to access social networking sites (SNSs) whenever and wherever they want. Such easy availability and accessibility may increase their vulnerability to addiction. Based on the social cognitive theory (SCT), we examined the impacts of outcome expectancies, self-efficacy, and impulsivity on young Chinese smartphone users’ addictive tendencies toward SNSs. Methods Two hundred seventy-seven Macau young smartphone users (116 males and 161 females; mean age = 26.62) filled out an online Chinese questionnaire concerning their usage of social networking sites via smartphones, addiction tendencies toward SNSs, impulsivity trait, outcome expectancies toward the use, and Internet self-efficacy. Results The findings revealed that those who spent more time on SNSs also reported higher addictive tendencies. Addictive tendencies were positively correlated with both outcome expectancies and impulsivity, but negatively associated with Internet self-efficacy. These three ...

Perceived prevalence of teasing and bullying predicts high school dropout rates.

Abstract: This prospective study of 276 Virginia public high schools found that the prevalence of teasing and bullying (PTB) as perceived by both 9th-grade students and teachers was predictive of dropout rates for this cohort 4 years later. Negative binomial regression indicated that one standard deviation increases in student- and teacher-reported PTB were associated with 16.5% and 10.8% increases in the number of dropouts, respectively, after controlling for the effects of other predictors, including school size, student body poverty and minority composition, community crime rates, and performance on standardized achievement testing. The predictive values of student and teacher perceptions of PTB were comparable in magnitude to the predictive values for other commonly recognized correlates of dropout rates. These results provide new evidence that the prevalence of peer victimization in high school is an important factor in high school academic performance. Language: en

Label-free luminescent oligonucleotide-based probes

Abstract: Breakthrough advances in chemistry and biology over the last two decades have vastly expanded the repertoire of nucleic acid structure and function with potential application in multiple areas of science and technology, including sensing and analytical applications. DNA oligonucleotides represent popular tools for the development of sensing platforms due to their low cost, rich structural polymorphism, and their ability to bind to cognate ligands with sensitivity and specificity rivaling those for protein enzymes and antibodies. In this review, we give an overview of the “label-free” approach that has been a particular focus of our group and others for the construction of luminescent DNA-based sensing platforms. The label-free strategy aims to overcome some of the drawbacks associated with the use of covalently-labeled oligonucleotides prevalent in electrochemical and optical platforms. Label-free DNA-based probes harness the selective interaction between luminescent dyes and functional oligonucleotides that exhibit a “structure-switching” response upon binding to analytes. Based on the numerous examples of label-free luminescent DNA-based probes reported recently, we envisage that this field would continue to thrive and mature in the years to come.

Multiview Hessian Discriminative Sparse Coding for Image Annotation

Abstract: Sparse coding represents a signal sparsely by using an overcomplete dictionary, and obtains promising performance in practical computer vision applications, especially for signal restoration tasks such as image denoising and image inpainting. In recent years, many discriminative sparse coding algorithms have been developed for classification problems, but they cannot naturally handle visual data represented by multiview features. In addition, existing sparse coding algorithms use graph Laplacian to model the local geometry of the data distribution. It has been identified that Laplacian regularization biases the solution towards a constant function which possibly leads to poor extrapolating power. In this paper, we present multiview Hessian discriminative sparse coding (mHDSC) which seamlessly integrates Hessian regularization with discriminative sparse coding for multiview learning problems. In particular, mHDSC exploits Hessian regularization to steer the solution which varies smoothly along geodesics in the manifold, and treats the label information as an additional view of feature for incorporating the discriminative power for image annotation. We conduct extensive experiments on PASCAL VOC'07 dataset and demonstrate the effectiveness of mHDSC for image annotation.

Real Earnings Management and Cost of Capital

Abstract: This study investigates whether a firm’s cost of equity capital is influenced by the extent of a firm’s real activities management. Using a large sample of U.S. firms, we find that our proxy for the cost of capital is positively associated with the extent of earnings management through the real activities manipulation after controlling for the effect of the accrual-based earnings management. We also provide evidence suggesting that this positive association stems from managerial opportunism rather than from the measurement errors in our real earnings management proxies. The main findings are robust to a battery of sensitivity tests. Collectively, our results suggest that real earnings management activities exacerbate the information quality of earnings used by outside investors, and thus the market demands a higher risk premium for these activities, which is incremental to the risk premium for the accrual-based earnings management.

Drug repositioning by structure-based virtual screening

Abstract: Approved drugs have favourable or validated pharmacokinetic properties and toxicological profiles, and the repositioning of existing drugs for new indications can potentially avoid expensive costs associated with early-stage testing of the hit compounds. In recent years, technological advances in virtual screening methodologies have allowed medicinal chemists to rapidly screen drug libraries for therapeutic activity against new biomolecular targets in a cost-effective manner. This review article outlines the basic principles and recent advances in structure-based virtual screening and highlights the powerful synergy of in silico techniques in drug repositioning as demonstrated in several recent reports.

Corporate Social Responsibility Reporting in China: An Overview and Comparison with Major Trends

Abstract: Given the scant literature of corporate social responsibility (CSR) reporting on mainland China, especially in the Western academia, the present paper aims at providing an overview of the CSR reporting requirements in that country A comparison with major reporting trends such as the adoption of GRI-G3 is made to further understand the development of CSR in China A literature review of prior studies is also conducted concerning CSR in China, especially those which are available only in the Chinese language In summary, the overview indicates that CSR reporting in China is at a very preliminary stage and more empirical research in this area is urgently called for Copyright © 2012 John Wiley & Sons, Ltd and ERP Environment

Generation of integration-free neural progenitor cells from cells in human urine

Abstract: Human neural stem cells hold great promise for research and therapy in neural disease. We describe the generation of integration-free and expandable human neural progenitor cells (NPCs). We combined an episomal system to deliver reprogramming factors with a chemically defined culture medium to reprogram epithelial-like cells from human urine into NPCs (hUiNPCs). These transgene-free hUiNPCs can self-renew and can differentiate into multiple functional neuronal subtypes and glial cells in vitro. Although functional in vivo analysis is still needed, we report that the cells survive and differentiate upon transplant into newborn rat brain.

Modeling Unobserved Heterogeneity Using Latent Profile Analysis: A Monte Carlo Simulation

Abstract: Latent profile analysis (LPA) has become a popular statistical method for modeling unobserved population heterogeneity in cross-sectionally sampled data, but very few empirical studies have examined the question of how well enumeration indexes accurately identify the correct number of latent profiles present. This Monte Carlo simulation study examined the ability of several classes of enumeration indexes to correctly identify the number of latent population profiles present under 3 different research design conditions: sample size, the number of observed variables used for LPA, and the separation distance among the latent profiles measured in Mahalanobis D units. Results showed that, for the homogeneous population (i.e., the population has k = 1 latent profile) conditions, many of the enumeration indexes used in LPA were able to correctly identify the single latent profile if variances and covariances were freely estimated. However, for a heterogeneous population (i.e., the population has k = 3 distinct l...

Short-Selling, Margin-Trading, and Price Efficiency: Evidence from the Chinese Market

Abstract: China launched a pilot scheme in March 2010 to lift the ban on short-selling and margin-trading for stocks on a designated list. We find that stocks experience negative returns when added to the list. After the ban is lifted, price efficiency increases while stock return volatility decreases. Panel data regressions reveal that intensified short-selling activities are associated with improved price efficiency. Short-sellers trade to eliminate overpricing by selling stocks with higher contemporaneous returns following a downward trend, and their trades predict future returns. In contrast, we find intensified margin-trading activities for stocks with lower contemporaneous returns, and these trades have no return predictive power.

Identification and Compensation of Piezoelectric Hysteresis Without Modeling Hysteresis Inverse

Abstract: This paper presents a new approach for hysteresis identification and compensation of piezoelectric actuators by resorting to an intelligent hysteresis model. In particular, a least squares support vector machine (LSSVM)-based hysteresis model is developed and used for both purposes of hysteresis identification and hysteresis compensation. By this way, the hysteresis inverse is not needed in the feedforward hysteresis compensator since the hysteresis model is directly used. To establish the LSSVM model, the problem of how to select input variables to convert the multivalued mapping into a single-valued one is addressed. The effectiveness of the presented idea is validated by a series of experimental studies on a piezoactuated system. Results show that the proposed approach is superior to the Bouc–Wen-model-based one in terms of both hysteresis modeling and compensation. The reported method is more computational effective than existing model-based hysteresis compensation approaches, and it is extensible to other smart actuator systems as well.

Modeling and High Dynamic Compensating the Rate-Dependent Hysteresis of Piezoelectric Actuators via a Novel Modified Inverse Preisach Model

Abstract: Hysteresis of a piezoelectric actuator is rate-dependent, but most hysteresis models are based on elementary rate-independent models, which are not suitable for modeling actuator behavior across a wide range of frequencies. This paper presents a novel modified inverse Preisach model to compensate the hysteresis of a piezoelectric actuator at varying frequency ranges. The classical Preisach model for hysteresis is introduced first, the identification of μ-function through least square method is conducted afterwards. The linearity property of the Preisach model is analyzed and verified by experiment. A novel modified inverse Preisach model featured with weighed sum of μ-density functions is proposed, which is based on the linearity property. The fast Fourier transform method is adopted to select the proper μ-density functions and weights to form a real-time online rate-dependent compensator for piezoceramic (PZTs) hysteresis. During experiments with tracking multifrequency composed signals, we have observed that the hysteresis features of the PZT can be consistently compensated. The experimental results show that the proposed open-loop hysteresis adjust method greatly improves the tracking control accuracy of the PZT.

When Do Global Leaders Learn Best to Develop Cultural Intelligence? An Investigation of the Moderating Role of Experiential Learning Style

Abstract: Cultural intelligence is believed to be an important quality for global leaders To understand how this quality can be developed from international experience, our study employs experiential learning theory to analyze the learning process We hypothesize that the extent to which the length of overseas work experience contributes to the development of cultural intelligence varies depending on the executives' learning styles Analyses of data collected from 294 international executives and graduate business students in China and Ireland indicated that the positive relationship between the length of overseas experience and cultural intelligence is strengthened when global executives have a divergent learning style, not when they have an assimilative, convergent, or accommodative learning style

Engineering Applications of Intelligent Monitoring and Control 2014

Abstract: 1 Department of Electromechanical Engineering, Faculty of Science and Technology, University of Macau, Avenida Padre Tomas Pereira Taipa, Macao, China 2 School of Control Science and Engineering, Shandong University, Jinan, Shandong 250061, China 3Department of Mechanical Engineering, The University of Auckland, 20 Symonds Street, Auckland, New Zealand 4Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan

A General Robust Linear Transceiver Design for Multi-Hop Amplify-and-Forward MIMO Relaying Systems

Abstract: In this paper, linear transceiver design for multi-hop amplify-and-forward (AF) multi-input multi-output (MIMO) relaying systems with Gaussian distributed channel estimation errors is investigated. Commonly used transceiver design criteria including weighted mean-square-error (MSE) minimization, capacity maximization, worst-MSE/MAX-MSE minimization and weighted sum-rate maximization, are considered and unified into a single matrix-variate optimization problem. A general robust design algorithm is proposed to solve the unified problem. Specifically, by exploiting majorization theory and properties of matrix-variate functions, the optimal structure of the robust transceiver is derived when either the covariance matrix of channel estimation errors seen from the transmitter side or the corresponding covariance matrix seen from the receiver side is proportional to an identity matrix. Based on the optimal structure, the original transceiver design problems are reduced to much simpler problems with only scalar variables whose solutions are readily obtained by an iterative water-filling algorithm. A number of existing transceiver design algorithms are found to be special cases of the proposed solution. The differences between our work and the existing related work are also discussed in detail. The performance advantages of the proposed robust designs are demonstrated by simulation results.

Chemistry, bioactivity and quality control of Dendrobium, a commonly used tonic herb in traditional Chinese medicine

Abstract: The fresh or dried stems of many Dendrobium species are well known as one of the most expensive tonics in traditional Chinese medicine Documented as a “superior grade” herbal medicine in the ancient text “Shen Nong’s Herbal Classic”, Dendrobium has been used for thousands of years and is now a popular health food worldwide The main chemical components of Dendrobium are alkaloids, aromatic compounds, sesquiterpenoids and polysaccharides, with multiple biological activities, including immunomodulatory, neuroprotective and anti-tumor effects, etc Various qualitative and quantitative methods have been developed for the quality evaluation of Dendrobium In this review, the research progress since the 1930s relating to the chemistry, bioactivity and quality control of Dendrobium is summarized, existing problems and prospects are also discussed

Perceived benefits, perceived risk, and trust: Influences on consumers' group buying behaviour

Abstract: Purpose – The purpose of this paper is to investigate how perceived benefits, perceived risk, and trust influence Chinese consumers' online group buying organized by institutional initiators.Design/methodology/approach – In total, 578 valid samples were collected via an online survey. Multiple regressions were used to test the research model.Findings – The results show that three perceived benefits (price benefit, convenience benefit, and recreational benefit) and three factors that together represent trust of the initiator (perceived reputation, structural assurance, and website trustworthiness) significantly positively influence consumers' attitudes toward online group buying.Originality/value – This study is the first one to specifically focus on how perceived benefits and perceived risks influence consumers' attitudes toward online group buying.