Hong W.,Yu Da University |
Chen T.-S.,National Taichung Institute of Technology
IEEE Transactions on Information Forensics and Security | Year: 2012
This paper proposes a new data-hiding method based on pixel pair matching (PPM). The basic idea of PPM is to use the values of pixel pair as a reference coordinate, and search a coordinate in the neighborhood set of this pixel pair according to a given message digit. The pixel pair is then replaced by the searched coordinate to conceal the digit. Exploiting modification direction (EMD) and diamond encoding (DE) are two data-hiding methods proposed recently based on PPM. The maximum capacity of EMD is 1.161 bpp and DE extends the payload of EMD by embedding digits in a larger notational system. The proposed method offers lower distortion than DE by providing more compact neighborhood sets and allowing embedded digits in any notational system. Compared with the optimal pixel adjustment process (OPAP) method, the proposed method always has lower distortion for various payloads. Experimental results reveal that the proposed method not only provides better performance than those of OPAP and DE, but also is secure under the detection of some well-known steganalysis techniques. © 2011 IEEE.
Yang M.-F.,Yu Da University
Mathematical and Computer Modelling | Year: 2010
Due to today's highly competitive environment, both reducing lead time and the associated inventory cost are critically important issues in supply chain. And, the consideration of time value effect is lacked in most previous researches. However, the effect of inflation is too critical to ignore. Therefore, we develop an integrated inventory model with crashing cost which was determined by the length of lead time is polynomial to recover the real inventory problems. The objective of this research is to minimize present value of the joint expected total cost over infinite time horizon. Then, we provide a solution algorithm to determine the optimal order quantity, the length of lead time and the number of lots which are delivered from the vendor to the buyer in the solution procedure. Numerical example is provided here to illustrate the solution procedure. © 2009 Elsevier Ltd. All rights reserved.
Yeh Y.-P.,Yu Da University
Journal of Air Transport Management | Year: 2014
The accessibility of information through the Internet has enables flight attendants to become more informed, as well as developing more control of their own affairs. Employee advocacy is related to the transparency of airlines' employment offers and the airlines' willingness to do what is best for their employees. After reviewing the relevant literature, this study focuses on how employee advocacy is influenced by the way employees are treated by their airlines. We explored strategies that airline administrations apply to employee advocacy, developed a research setting, analyzed the factors involved, and developed a casual model of the antecedents and consequences of employee advocacy. We formulated 5 hypotheses. Data were collected, using a questionnaire survey of flight attendants in Taiwanese airlines. All hypotheses were verified with data from a sample of the respondents, by using a structural equation model. Our results indicated that employee advocacy is positively related to flight attendants' job satisfaction and commitment to the organization. Organizational innovation, supervisor support, and employee empowerment are positively related to employee advocacy. Finally, this study concludes by discussing managerial implications and providing suggestions for future research. © 2014 Elsevier Ltd.
Wu S.-L.,Yu Da University
Food Control | Year: 2012
The aim of this study was to analyze food safety control systems (FSCS) in selected hotels in Taiwan in order to identify current issues and future trends in the hotel industry. Fourteen interviews were conducted with personnel in six large international tourist hotels with a FSCS in place. Analysis of the interviews indicated that a hotel's food safety standards and operations depended significantly on the attitudes of the hotel management. Public concern, competitive advantage and the government's food safety policies all had less influence on the implementation and maintenance of a FSCS than the ongoing support of management. Hotel managements hope, therefore, that the government will educate the public on food safety and provide incentives that enable hotels to adopt FSCS strategies while reducing the cost. The study contributes to the development of theory relating to the implementation of food safety strategies, particularly for the hotel industry. © 2012 Elsevier Ltd.
Hong W.,Yu Da University
Optics Communications | Year: 2012
Tai et al. proposed a reversible data embedding method based on histogram shifting and achieved an excellent embedding performance. Their method shifts the absolute difference of two consecutive pixels for data embedment, and employs an embedding level to control the payload. However, the shifting of absolute difference reduces the number of embeddable spaces and results in a reduction in payload. Instead of shifting the absolute differences, this paper proposes an adaptive method to increase the number of embeddable spaces by referencing a dual binary tree. We also adopt a better predictor and employ an error energy estimator to reduce the number of non-embeddable prediction errors. The experimental results reveal that the proposed method significantly improves the image quality and payload of Tai et al.'s works, especially at low embedding level. © 2011 Elsevier B.V. All rights reserved.