281 research outputs found

    The causal relationships between components of customer-based brand equity for a destination: Evidence from South Korean tourists in Danang city, Vietnam

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    The main purpose of this study is to examine the causal relationships between components of customer-based brand equity for a tourist destination. We have collected data from 252 South Korean tourists in Danang City and tested some hypotheses by applying structural equation modeling (SEM). Results show that: (1) destination brand awareness has a significant and positive effect on destination brand image, but not on destination perceived quality and destination brand loyalty; (2) destination brand image has positive and direct influences on destination perceived quality and destination brand loyalty; and (3) destination perceived quality has significant positive impacts on destination brand loyalty. Lastly, these findings have managerial implications for decision makers

    The impact of oil prices, real effective exchange rate and inflation on economic activity: Novel evidence for Vietnam

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    The goal of this paper is to examine the impact of oil prices on Vietnam's economic activity using vector autoregressive (VAR) modeling and cointegration techniques. We use monthly data for the period 1995-2009 and include inflation and the real effective exchange rate as additional determinants of economic activity. We find evidence of a long-run relationship between oil prices, inflation, exchange rate, and economic activity. The results suggest that both oil prices and the real effective exchange rates have strongly significant impact on economic activity. An increase in oil price or depreciation may enhance economic activity. Vietnamese economic activity is influenced more by changes of value of Vietnamese currency than the fluctuations of oil prices. Inflation has a positive impact on economic activity however its impact is not highly significant. This suggests that moderate inflation is helpful rather than harmful to economic activity.Oil price, Economic activity, Vietnam

    Active fault-tolerance of the unmanned aerial vehicle automatic control systems

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    This paper presents an introductory overview of principles of the three-layer hierarchy of active fault-tolerance, providing, determination of the fault type with as many details as enough to get recoverable fault reason and failure toleration by flexible redundancy using; the conception of active fault-tolerant control in abnormal modes is described. Developed models and methods of a systematic approach to fault tolerance in the direction of the effective use of the signal, parametric and structural redundancies and selection of parrying tools. Performed experimental researches of the unmanned aerial vehicle (UAV) automatic control systems (ACS)

    Optimal generation for wind-thermal power plant systems with multiple fuel sources

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    In this paper, the combined wind and thermal power plant systems are operated optimally to reduce the total fossil fuel cost (TFFC) of all thermal power plants and supply enough power energy to loads. The objective of reducing TFFC is implemented by using antlion algorithm (ALA), particle swarm optimization (PSO) and Cuckoo search algorithm (CSA). The best method is then determined based on the obtained TFFC from the three methods as dealing with two study cases. Two systems with eleven units including one wind power plant (WPP) and ten thermal power plants are optimally operated. The two systems have the same characteristic of MFSs but the valve loading effects (VLEs) on thermal power plants are only considered in the second system. The comparisons of TFFC from the two systems indicate that CSA is more powerful than ALA and PSO. Furthermore, CSA is also superior to the two methods in terms of faster search process. Consequently, CSA is a powerful method for the problem of optimal generation for wind-thermal power plant systems with consideration of MFSs from thermal power plants

    Minimize electricity generation cost for large scale wind- thermal systems considering prohibited operating zone and power reserve constraints

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    Wind power plants (WPs) play a very important role in the power systems because thermal power plants (TPs) suffers from shortcomings of expensive cost and limited fossil fuels. As compared to other renewable energies, WPs are more effective because it can produce electricity all a day from the morning to the evening. Consequently, this paper integrates the optimal power generation of TPs and WPs to absolutely exploit the energy from WPs and reduce the total electricity generation cost of TPs. The target can be reached by employing a proposed method, called one evaluation-based cuckoo search algorithm (OEB-CSA), which is developed from cuckoo search algorithm (CSA). In addition, conventional particle swarm optimization (PSO) is also implemented for comparison. Two test systems with thirty TPs considering prohibited working zone and power reserve constraints are employed. The first system has one wind power plant (WP) while the second one has two WPs. The result comparisons indicate that OEB-CSA can be the best method for the combined systems with WPs and TPs

    About an approximate method to solve the static boundary value problems in the isotropic hardening elastic-plastic solid

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    The paper presents the theory, model, weak form, finite element method and return-mapping algorithm for the isotropic hardening elastic-plastic problem. Then applying the algorithm to numerically simulate a variety of plane strain problems

    Development of a SCARA robot arm for palletizing applications based on computer vision

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    This paper develops a computer vision system integrated with a SCARA robot arm to pick and place objects. A novel method to calculate the 3D coordinates of the objects from a camera is proposed. This method helps simplify the camera calibration process. It requires no knowledge of camera modeling and mathematical knowledge of coordinate transformations. The least square method will predate the Equation describing the relationship between pixel coordinates and 3D coordinates. An image processing algorithm is presented to detect objects by color or pixel intensity (thresholding method). The pixel coordinates of the objects are then converted to 3D coordinates. The inverse kinematic Equation is applied to find the joint angles of the SCARA robot. A palletizing application is implemented to test the accuracy of the proposed method. The kinematic Equation of the robot arm is presented to convert the 3D position of the objects to the robot joint angles. So, the robot moves exactly to the required positions by providing suitable rotational movements for each robot joint. The experiment results show that the robot can pick and place 27 boxes on the conveyor to the pallet with an average time of 2.8s per box. The positions of the boxes were determined with an average error of 0.5112mm and 0.6838mm in the X and Y directions, respectively

    MỘT SỐ KẾT QUẢ NGHIÊN CỨU BƯỚC ĐẦU VỀ ĐỘNG LỰC TRẦM TÍCH LƠ LỬNG TRONG MÙA LŨ TẠI VÙNG BIỂN VEN BỜ CỬA SÔNG HẬU

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    Land-ocean interactions in the coastal zone are severely influenced by tidal processces. In regions of high sediment discharge like the coast of Hau river estuary, these processes are even more significant when we analyse data in flood season (September) - which belongs to Agreement of Cooperation in Science and Technology between Vietnam and US (2013-2015) and project VAST-DLT.06/15-16 (2015-2016). Our goal is to investigate the sedimentation  processes. Additionally, we investigated the influence of the tidal currents in relation to the suspended sediment. Salinity (PSU - Practical salinity unit), suspended sediment concentration (NTU - Nephelometric Turbidity Units) were measured by Compac-CTD (Depth temperature conductivity chlorophyll turbidity) and OBS-3A (Turbidity and Temperature Monitoring System) instruments. The results show that the suspended sediment concentration (SSC) correlate with tidal current velocities. The tidal current velocities are up to 60 cm/s near the surface and 40 cm/s near the bottom, increasing SSC in the water column at bottom layer (24 NTU) and decreasing SSC at surface layer (8 NTU). Processes of sediment transport and deposition in flood tide in flood season are influenced by tidal currents more significantly than those in dry season. This leads to an asymmetry of the tidal ellipses and the different deposition between seasons. The analytical results imply the influence of tide and tidal currents on SSC in the coast of Hau river estuary, hence, the spread, sea water and fresh water mixing processes have difference during tidal phases and seasons.Các mối tương tác biển - đất liền trong vùng ven bờ bị chi phối chủ yếu bởi các quá trình thủy động lực như sóng, dòng chảy, lưu lượng nước sông, thủy triều trong đó thủy triều đóng vai trò quan trọng. Tại các khu vực có lưu lượng phù sa lớn như vùng ven biển sông Hậu, các quá trình này càng trở nên rõ rệt khi phân tích từ số liệu khảo sát trong thời kỳ mùa lũ (tháng 9) thuộc chương trình hợp tác khoa học và công nghệ giữa Việt Nam và Hoa Kỳ (2013 - 2015) và đề tài độc lập mã số VAST-ĐLT.06/15-16 (2015 - 2016). Trong chuyến khảo sát này, mục đích là điều tra sự lắng đọng và phân bố theo không gian, thời gian của hàm lượng trầm tích lơ lửng. Ngoài ra, chúng tôi còn khảo sát ảnh hưởng của dòng triều trong mối tương quan với hàm lượng trầm tích lơ lửng. Độ muối (đơn vị PSU - Practical Salinity Unit), hàm lượng trầm tích lơ lửng (đơn vị đo NTU - Nephelometric Turbidity Units) được đo bằng thiết bị Compac-CTD (Depth temperature conductivity chlorophyll turbidity), và thiết bị đo độ đục OBS-3A (Turbidity and Temperature Monitoring System). Kết quả nghiên cứu cho thấy hàm lượng trầm tích lơ lửng tương quan với vận tốc dòng chảy. Tốc độ dòng chảy khi triều lên đến 60 cm/s ở lớp mặt và 40 cm/s ở đáy tạo nên sự tăng nồng độ trầm tích lơ lửng trong cột nước ở tầng đáy 24 NTU và 8 NTU tại tầng mặt. Trong pha triều lên, quá trình vận chuyển và lắng đọng trầm tích lơ lửng bị chi phối bởi dòng triều dài hơn so với mùa khô. Điều này cho thấy sự bất đối xứng của elip thủy triều và dẫn đến sự lắng đọng trầm tích lơ lửng trong các mùa là khác nhau. Từ kết quả phân tích có thể thấy vùng biển ven bờ cửa sông Hậu, hàm lượng trầm tích lơ lửng chịu sự chi phối bởi dòng chảy triều và thủy triều là rất lớn, do đó quá trình lan truyền, xáo trộn nước sông và biển có sự khác biệt đáng kể trong các điều kiện triều và điều kiện mùa

    Smart Shopping Assistant: A Multimedia and Social Media Augmented System with Mobile Devices to Enhance Customers’ Experience and Interaction

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    Multimedia, social media content, and interaction are common means to attract customers in shopping. However these features are not always fully available for customers when they go shopping in physical shopping centers. The authors propose Smart Shopping Assistant, a multimedia and social media augmented system on mobile devices to enhance users’ experience and interaction in shopping. Smart Shopping turns a regular mobile device into a special prism so that a customer can enjoy multimedia, get useful social media related to a product, give feedbacks or make actions on a product during shopping. The system is specified as a flexible framework to take advantages of different visual descriptors and web information extraction modules. Experimental results show that Smart Shopping can process and provide augmented data in a realtime-manner. Smart Shopping can be used to attract more customers and to build an online social community of customers to share their interests in shopping
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