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A hybrid encoding method is used to assemble the double-random phase-encoding technique and the binary encoding method. Because the double-random phase-encoding technique is robust for noises and the binary encoding method is free of using external keys, the proposed hybrid encoding method has their advantages. The hybrid encoding method first encodes a covert image to form a complexnumber matrix by using the double-random phase-encoding technique, where two random real-number matrices are used to increase the security of the encoding work. Then the elements of the two random real-number matrices and the elements of the complex-number matrix are encoded to form a binary-bit string by using the binary encoding method. Finally, the binary data in the binary-bit string are encoded into a host image to form an overt image with hidden information by using a gray-value modulation method. The decoding work is easy for authorized people, but it is very difficult for unauthorized people. Therefore, the proposed hybrid encoding method is a very useful encoding method. © 2010 Optical Society of America.

Lin K.T.,St. Johns University Taiwan
Applied Optics | Year: 2010

Novel information hiding for digital images based on binary encoding methods and pixel scrambling techniques is presented. First, a pixel scrambling technique is used to rearrange the pixels of a covert image to form a scrambled matrix by using a specified scrambling rule. Then, the gray values of all the pixels in the scrambled matrix are sequentially transformed into many sets of eight-digit binary codes. Subsequently, the eight-digit binary codes are encoded into a host image to form an overt image by using a specific encoding rule. Besides the eight-digit binary codes (information codes), the overt image contains five other groups of binary codes (specification codes), i.e., identification codes, gray-level codes, dimension codes, scrambling number codes, and scrambling time codes, to denote the parameters used for scrambling and encoding. According to the test results, the proposed method performs well. Moreover, the overt image and the host image look almost the same, and the decoded covert image is exactly the same as the original covert image. © 2010 Optical Society of America.

Pneumatic muscle actuators have the highest power/weight ratio and power/volume ratio among actuators of all types. Therefore, they can be used not only in rehabilitation engineering, but also as actuators in robots, including industrial robots and therapy robots. It is difficult to achieve excellent control performance using classical control methods because the compressibility of gas and the nonlinear elasticity of bladder containers cause parameter variations. An adaptive self-organizing fuzzy sliding mode control (ASOFSMC) is developed in this study. Its fuzzy sliding surface can help reduce the number of fuzzy rule. The self-organizing learning mechanism is employed to modify fuzzy rules on-line. The model-matching technique is then adopted to adjust the scaling factors. Finally, the Lyapunov theory is employed to prove the stability of the ASOFSMC. Experimental results show that this control strategy can attain excellent control performance. © 2009 Elsevier Ltd. All rights reserved.

Yang S.-Y.,St. Johns University Taiwan
Expert Systems with Applications | Year: 2010

With the growing popularity of Internet technology, information is increasing in a geometric-progressively manner. How to find advantage information to meet user queries in the information torrent of Internet has become the first goal of lots of scholars. This paper focused on developing an ontology-supported information integration and recommendation system for scholars. Not only can it rapidly integrate specific domain documents, but also it can extract important information from them by information integration and recommendation ranking. The core technologies adopted in this study included: ontology-supported webpage crawler, webpage classifier, information extractor, information recommender, and a user integration interface. The preliminary experiment outcomes proved both the webpage crawler and classifier in the core technology can achieve an excellent precision rate of webpage treatment and the reliability and validation measurements of the whole system performance can also achieve the high-level outcomes of information recommendation. Further, this paper also discussed and examined the advantages and shortcomings of the construction of a recommendation system with different approaches and accordingly provided the design philosophy of customized services for recommendation systems. © 2010 Elsevier Ltd. All rights reserved.

Yang S.-Y.,St. Johns University Taiwan
Expert Systems with Applications | Year: 2010

This paper proposed the use of ontology-supported website models to provide a semantic level solution for an information agent so that it can provide fast, precise, and stable query results. We have based on the technique to develop a focused crawler, namely, OntoCrawler which can benefit both user requests and domain semantics. The technique in this research has practically applied on Google and Yahoo searching engines to actively search for webpages of related information, and the experiment outcomes indicated that this technique could definitely up-rise precision rate and recall rate of webpage query. Equipped with this technique, we have developed an ontology-supported information agent shell in Scholar domain which manifests the following interesting features: ontology-supported construction of website models, website models-supported website model expansion, website models-supported webpage retrieval, high-level outcomes of information recommendation, and accordingly proved the feasibility of the related techniques proposed in this paper. © 2010 Elsevier Ltd. All rights reserved.

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