• 제목/요약/키워드: Macau

검색결과 66건 처리시간 0.026초

One-dimensional consolidation with asymmetrical exponential drainage boundary

  • Mei, Guo-Xiong;Lok, Thomas M.H.;Xia, Jun;Wu, Sheng Shen
    • Geomechanics and Engineering
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    • 제6권1호
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    • pp.47-63
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    • 2014
  • In this paper, asymmetric drainage boundaries modeled by exponential functions which can simulate intermediate drainage from pervious to impervious boundary is proposed for the one-dimensional consolidation problem, and the solution for the new boundary conditions was derived. The new boundary conditions satisfy the initial and the steady state conditions, and the solution for the new boundary conditions can be degraded to the conventional solution by Terzaghi. Convergence study on the infinite series solution showed that only one term in the series is needed to meet the precision requirement for larger degree of consolidation, and that more terms in the series for smaller degree of consolidation. Comparisons between the present solution with those by Terzaghi and Gray are also provided.

Smooth Formation Navigation of Multiple Mobile Robots for Avoiding Moving Obstacles

  • Chen Xin;Li Yangmin
    • International Journal of Control, Automation, and Systems
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    • 제4권4호
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    • pp.466-479
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    • 2006
  • This paper addresses a formation navigation issue for a group of mobile robots passing through an environment with either static or moving obstacles meanwhile keeping a fixed formation shape. Based on Lyapunov function and graph theory, a NN formation control is proposed, which guarantees to maintain a formation if the formation pattern is $C^k,\;k\geq1$. In the process of navigation, the leader can generate a proper trajectory to lead formation and avoid moving obstacles according to the obtained information. An evolutionary computational technique using particle swarm optimization (PSO) is proposed for motion planning so that the formation is kept as $C^1$ function. The simulation results demonstrate that this algorithm is effective and the experimental studies validate the formation ability of the multiple mobile robots system.

A Numerical Investigation of Indoor Air Quality with CFD

  • Sin V. K;Sun H. I
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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    • pp.207-208
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    • 2003
  • Increasing interest in indoor air quality (IAQ) control has been found because of its serious effect on human health. To evaluate IAQ, thermal comfort in terms of temperature and velocity distributions of indoor air has to be analyzed in detail. Choice of location for installation of air-conditioner in a building will affect the performance of cooling effect and thermal comfort on the occupants, which in turn will affect the indoor air quality (IAQ) of the building. In this paper, we present a discussion on the proper location of the air-conditioner in order to obtain good thermal comfort for occupant of a typical bedroom in Macao. A set of carefully designed numerical experiments is run with the Computational Fluid Dynamics (CFD) software FLOVENT 3.2 [1]. Reynolds averaged Navier-Stokes equations are solved with finite volume technique and turbulence effects upon the mean flow characteristics is modeled with the k - & model. Assumption of steady state environment is made and only convective and conductive heat transfer from the occupant and air-conditioner are being concerned.

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Overview of flexure-based compliant microgrippers

  • Aia, Wenji;Xu, Qingsong
    • Advances in robotics research
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    • 제1권1호
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    • pp.1-19
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    • 2014
  • Microgripper is an essential device in the micro-operation system. It can convert other types of energy into mechanical energy and produce clamp movement with required chucking force, which enables it a broad application prospect in the domain of tiny components' processing and assembly, biomedicine and optics, etc. The performance of a microgripper is dependent on its power supply, type of drive, mechanism structure, sensing components, and controller. This paper presents a state-of-the-art survey of recent development on flexure-based microgrippers. According to the drive type, the existing microgrippers can be mainly classified as electrostatic microgripper, electrothermal microgripper, electromagnetic microgripper, piezoelectric microgripper, and shape memory alloy microgripper. Additionally, some different mechanisms, sensors, and control methods that are used in microgripper system are reviewed. The key issue of how to choose those components in microgripper system design is also addressed.

Sliding Wear and Corrosion Resistance of Copper-based Overhead Catenary for Traction Systems

  • Kwok, C.T.;Wong, P.K.;Man, H.C.;Cheng, F.T.
    • International Journal of Railway
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    • 제3권1호
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    • pp.19-27
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    • 2010
  • In the present study, the electrical sliding wear and corrosion resistance of pure copper (Cu) and six age-hardened copper alloys (CuCr, CuZr, CuCrZr, CuNiSiCr, CuBe and CuBeNi) were investigated by a pin-on-disc tribometer and electrochemical measurement. Various copper-based alloys in the form of cylindrical pin were forced to slide against a counterface stainless steel disc in air under unlubricated condition at a sliding velocity of 31 km/h under normal load up to 20 N with and without electric current. The worn surface of and wear debris from the specimens were studied by scanning electron microscopy. Both mechanical wear and electrical arc erosion were the wear mechanisms for the alloys worn at 50 A. Owing to its good electrical conductivity, high wear and corrosion resistance, CuCrZr is a promising candidate as the overhead catenary material for electric traction systems.

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Domestic Tourists' Perception of Hotel Websites in Thailand

  • Chitlada Pinthong;Sunny Sun;Huiyue Ye;Rob Law
    • Journal of Smart Tourism
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    • 제3권4호
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    • pp.5-15
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    • 2023
  • With the growing trend of online global market, customers have further technological capabilities in searching for information and online shopping on the Internet. In addition, electronic word-of-mouth (eWOM) is a significant factor that influences customer purchase intention. However, the perspective of online users on hotel websites is still in its infancy, especially in various cultural contexts. The current study examined a theoretical framework of hotel websites to understand how online users perceive the importance of hotel websites with regard to influencing purchase intention, within the content of Thai online users through an online questionnaire survey. Findings show that usability positively influences online Thai users' satisfaction. Moreover, eWOM has a significant positive influence on satisfaction, but eWOM has an indirect effect on the intention to purchase. Practical implications are further discussed.

Strategic Framework for Website Evaluation based on a Review of Tourism and Hospitality Literature from 2010-2023

  • Xiaonan Li;Dave C. F. Chan;Rob Law
    • Journal of Smart Tourism
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    • 제3권3호
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    • pp.17-27
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    • 2023
  • This study examines the scientific publications on website evaluation in hospitality and tourism from 2010 to 2023 through a systematic review and discusses implications for future research. The reviewed literature from publication years, journals, research methods, website-related stakeholders, context, various forms of Internet presence (Internet forms), and theories are analyzed to create a comprehensive website evaluation dimension. Furthermore, a conceptual framework is developed to show the relationship between the website characteristics, stakeholders-channels interaction, and stakeholders' reactions. The proposed website evaluation framework in hospitality and tourism synthesizes the existing knowledge, identifies gaps, and further advances our understanding of this research area.

Predicting Health Communication Patterns in Follower-Influencer Networks: The Case of Taiwan Amid COVID-19

  • Chang, Angela;Jiao, Wen
    • Asian Journal for Public Opinion Research
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    • 제8권3호
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    • pp.246-264
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    • 2020
  • As netizens increasingly utilize social media to obtain and engage with information, this study aims to determine the extent to which the follower-influencer interaction is manifested and strengthened. To analyze information related to the novel coronavirus disease (COVID-19), a total of 62,119 online posts from 11 Internet forums were examined to find a relationship between followers and influencers in Taiwan. These forums are PTT, SOGO, Ck101, Plurk, Mobile01, TalkFetnet, Gamez, PlaySport, Dcard, Eyny, and PCDVD. The variables that were the best predictors of influencer classification were strong influences, engagements, and hot values across 11 Internet forums. Learning the response to the COVID-19 pandemic is vital because public actions could have been fueled by stigmatizing terms that may harm public health and well-being. The results questioned the conventional diffusion of traditional news sources because the influencers brought widespread attention to the health threat issues in the early outbreak stages. This study enhances the understanding of forum types, follower engagement, and influencers' impact maximization in social networks. The conclusion provides insight into the relationships and information diffusion mechanisms to ensure accurate health information dissemination.

Stream-based Biomedical Classification Algorithms for Analyzing Biosignals

  • Fong, Simon;Hang, Yang;Mohammed, Sabah;Fiaidhi, Jinan
    • Journal of Information Processing Systems
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    • 제7권4호
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    • pp.717-732
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    • 2011
  • Classification in biomedical applications is an important task that predicts or classifies an outcome based on a given set of input variables such as diagnostic tests or the symptoms of a patient. Traditionally the classification algorithms would have to digest a stationary set of historical data in order to train up a decision-tree model and the learned model could then be used for testing new samples. However, a new breed of classification called stream-based classification can handle continuous data streams, which are ever evolving, unbound, and unstructured, for instance--biosignal live feeds. These emerging algorithms can potentially be used for real-time classification over biosignal data streams like EEG and ECG, etc. This paper presents a pioneer effort that studies the feasibility of classification algorithms for analyzing biosignals in the forms of infinite data streams. First, a performance comparison is made between traditional and stream-based classification. The results show that accuracy declines intermittently for traditional classification due to the requirement of model re-learning as new data arrives. Second, we show by a simulation that biosignal data streams can be processed with a satisfactory level of performance in terms of accuracy, memory requirement, and speed, by using a collection of stream-mining algorithms called Optimized Very Fast Decision Trees. The algorithms can effectively serve as a corner-stone technology for real-time classification in future biomedical applications.