Time filter

Source Type

Kaohsiung, Taiwan

Chen C.H.,NSYSU | Tang Y.L.,CYUT | Hsieh W.S.,NSYSU | Hsieh W.S.,Slovak University of Technology in Bratislava
Proceedings - 2014 International Symposium on Computer, Consumer and Control, IS3C 2014

In this paper, we describe an authentication and recovery scheme for color image protection based on adaptive encoding. The image blocks are categorized based on their contents and different encoding schemes are applied according to their types. Such adaptive encoding results in better image quality and more robust image authentication. The approximations of the luminance and chromatic channels are carefully calculated, and for the purpose of reducing the data size, the differential coding is used to encode the channels with variable size according the characteristic of the block. The recovery data which represents the approximation and the detail of the image is embedded for data protection. The necessary data is well protected by using the error correcting coding (ECC) and duplication. The experimental results demonstrate that our technique is able to identify and localize image tampering, while preserving high quality for both watermarked and recovered images. © 2014 IEEE. Source

Quadir B.,NSYSU | Chen N.-S.,NSYSU
Proceedings - 2013 IEEE 13th International Conference on Advanced Learning Technologies, ICALT 2013

The purpose of this study was to gain greater insights into the habit factors that contribute to one's learning effectiveness. Therefore, present study developed the 'Learner's Digest' blog (i.e., a learning blog) with relevant features including information retrieval, user friendly context and learner-learner interaction. It was designed to provide interesting blog posts to facilitate meaningful learning. In 'Learner's Digest' blog learners were participated as blog readers. This paper investigated how one's reading habit contributes to his/her learning effectiveness participating towards Learner's Digest blog. A survey was conducted for understanding the relationship between individual's reading habit, in terms of the reading attitude / behavioral pattern, and the learning effectiveness of participation towards a learning blog, in terms of learning performance and satisfaction. A total of 73 blog readers from 'Learner's Digest' participated in the study. Hypotheses were tested and data was analyzed using simple linear regression and logistic regression analysis. The result revealed that reading habit is a significant predictor of learning effectiveness. A subsequent analysis showed that people with a stronger reading habit is a significant predictor to greater learning effectiveness. Discussions and implications of this study are also presented. © 2013 IEEE. Source

For an offshore platform applied to wave-energy conversion system, in order to catch the maximum waves to generate more powers, similar to wind-energy power generators, a range of angles for the devices normal to the propagating direction of incident waves is required, particularly when the power converting system has directional preference. A single mooring system would allow the offshore wave-energy conversion system to turn freely in accordance to the action of strong directions of propagating waves and in this way, most energy induced from the incident waves can be caught and converted into reusable powers. The aim of this study is to find the efficiency of single-moored platform applied to a wave power converting system through an experimental test in the water tank. © (2013) Trans Tech Publications, Switzerland. Source

Lee H.H.,NSYSU | Wang C.-W.,NSYSU
Advanced Materials Research

For an infrastructure construction located in marine environments, maintaining good durability for the structures always imposes serious challenges, especially for the structure made of reinforced concrete. Concrete exposed to marine environment may deteriorate as a result of combined effects of both physical and chemical actions from marine environment. Corrosion of the reinforced steel bars that are embedded in the concrete is the most serious problem. Therefore, a method to protect the reinforced concrete in the marine environment from damages due to material deterioration and corrosion is proposed in this study. The method is through the application of bentonite material by utilizing its very finely divided form so that the larger capillary pores in concrete can be filled up. In this way, the impermeability of concrete material can be enhanced and then improve the corrosion resistant ability of the material. © (2013) Trans Tech Publications, Switzerland. Source

Chen Y.-Y.,NSYSU | Chen Y.-Y.,International Wave Dynamics Research Center | Chen H.-S.,NSYSU
Ocean Engineering

A three-dimensional (3D) Lagrangian solution up to the fifth-order is found for the Boundary Value Problem (BVP) of irrotational, progressive water waves propagating in the presence of uniform current in water of constant depth. The BVP is formulated in the Lagrangian framework which uses Lagrangian label (a,b,c) and time t as the independent variables. The (a,b,c) of a particle in wave motion are the coordinates of the particle position in the still water. In the solution, wave-current interaction is embedded in the Lagrangian velocity potential in such way that pressure is not affected by current in the wave-current field. In this study, we present motion properties of particles such as the particle motion period, drift velocity, the Lagrangian mean level, and the 3D particle trajectory and streakline, aspects that are hardly described by the Eulerian solution. It is found that the particle motion period is always larger than the progressive wave period. As the wave-current becomes steady motion, the stable wavy track of the particle motion may exist in the wave-current field. When currents vanish, the present solution deduces to the same solution of the progressive wave propagation by Chen et al. (2010). © 2014 Elsevier Ltd. Source

Discover hidden collaborations