Bidirectional Transmission Using Tunable Fiber Lasers and Injection-Locked Fabry–PÉrot Laser Diodes for WDM Access Networks

We propose and demonstrate the use of fiber ring lasers and Fabry-Perot laser diodes (FP-LDs) for wavelength-division-multiplexing access networks. The fiber ring laser not only generates downstream data traffic but also serves as the wavelength-selecting injection light source for the FP-LD located at the subscriber site. Moreover, it is wavelength tunable and can be applied to dynamic wavelength assignment networks. The ring laser has a tunable range of 30 nm in the C-band and a power fluctuation smaller than 0.6 dB. For 10-Gb/s downstream and 1.25-Gb/s upstream transmissions over 10-km single-mode fiber, power penalties less than 0.9 and 0.5 dB are demonstrated, respectively. A 40-dB sidemode suppression ratio is obtained for the FP-LD injection-locking at 1544.8 nm.     

Second-order harmonic distortion and optimal fiber length in erbium-doped fiber amplifiers

The gain of an erbium-doped fiber amplifier (EDFA) operating in the kHz regimes and its second-order harmonic distortion (SBD) are studied. Using the rate and beam-propagation equations, we have shown the dependences of the distortion on the pump power, the modulation frequency, and the position along the fiber. Moreover, it is found that the SHD is the smallest when the fiber has an optimal length for the maximum gain. A relation between the optimal length and fiber parameters is presented for calculating easily the optimal fiber length in an EDFA.     

Mean arterial pressure control system using model predictive control and particle swarm optimization

Microsystem Technologies - Linear controllers have been designed to regulate mean arterial pressure (MAP) in treating various cardiovascular diseases. For patients with hemodynamic fluctuations,...     

Recover the tampered image based on VQ indexing

In this paper, a tampered image recovery scheme is proposed by creating an index table of the original image via vector quantization (VQ) and embedding it into the original image as a basis for recovery. In order to complete the goal of image authentication and recovery, Wong's watermarking scheme [P.W. Wong, N. Memon, Secret an public key image watermarking schemes for image authentication and ownership verification, IEEE Trans. Image Process 10 (10) (2001) 1593–1601] is employed to perform tamper detection. Wong's watermarking scheme can be used to accurately locate tampered regions. If an image has been tampered, the index table can be used to recover the tampered regions. The experimental results indicate that our scheme has the higher probability of image recovery. Besides, compared with Lee and Lin's [Dual watermark for image tamper detection and recovery, Pattern Recognition 41 (2008) 3497–3506] scheme, our scheme provides not only a better quality of recovered images but also better results at edge regions.     

Application of SPICE simulation to study WDM and SCM systems using EDFAs with chirping

The authors have proposed an equivalent electrical circuit model of erbium-doped fiber amplifiers (EDFAs), including the chirping effect for teaching or studying the distortions and performance of lightwave transmission systems. Through the aid of a SPICE circuit simulator, its validity is demonstrated by analyzing the cross modulations of an eight-channel wavelength division multiplexing system. The intermodulations in an amplitude modulation-subcarrier multiplexing (SCM) system are demonstrated. The channel-number dependence of the composite second-order distortion in a 42-channel SCM system is shown, and its applications to analyze other systems are also discussed.     

A robust associative watermarking technique based on vector quantization

In this paper, the concepts of vector quantization (VQ) and association rules in data mining are employed to propose a robust watermarking technique. Unlike ordinary or traditional watermarking techniques, our approach hides association rules of the watermark, instead of the whole watermark; in other words, the embedded information is the association rules of the watermark. First, VQ encoding is performed on the original image and watermark to generate the index tables, and from which association rules are further mined. Subsequently, by embedding the association rules of the watermark into the association rules of the original image, the purpose for watermarking is accomplished. Finally, VQ decoding technique is applied to reconstruct the watermarked image from the watermarked index table. Experimental results show that our proposed method achieves effective resistance against several image processings such as blurring, sharpening, adding in Gaussian noise, cropping, and JPEG lossy compression. Moreover, the embedding capacity is also significantly increased, so any a complex watermark image is still acceptable in this method.     

Computer-aided analysis of distortions in SCM systems with EDFAs including chirping effect

In this paper, we have applied an equivalent electrical circuit model of erbium-doped fiber amplifier (EDFA) including chirping effect to analyze the distortions in subcarrier multiplexing (SCM) systems. The model is simple and convenient for analyzing the distortions and performance of lightwave transmission systems using EDFAs, through the aid of a SPICE circuit simulator. The performance evaluation is shown of a 42-channel SCM EDFA system, including the composite second-order distortions (CSO), the allowable modulation index, and the limit on the number of channels.     

A data mining approach to database compression

Data mining can dig out valuable information from databases to assist a business in approaching knowledge discovery and improving business intelligence. Database stores large structured data. The amount of data increases due to the advanced database technology and extensive use of information systems. Despite the price drop of storage devices, it is still important to develop efficient techniques for database compression. This paper develops a database compression method by eliminating redundant data, which often exist in transaction database. The proposed approach uses a data mining structure to extract association rules from a database. Redundant data will then be replaced by means of compression rules. A heuristic method is designed to resolve the conflicts of the compression rules. To prove its efficiency and effectiveness, the proposed approach is compared with two other database compression methods. Chin-Feng Lee is an associate professor with the Department of Information Management at Chaoyang University of Technology, Taiwan, R.O.C. She received her M.S. and Ph.D. degrees in 1994 and 1998, respectively, from the Department of Computer Science and Information Engineering at National Chung Cheng University. Her current research interests include database design, image processing and data mining techniques. S. Wesley Changchien is a professor with the Institute of Electronic Commerce at National Chung-Hsing University, Taiwan, R.O.C. He received a BS degree in Mechanical Engineering (1989) and completed his MS (1993) and Ph.D. (1996) degrees in Industrial Engineering at State University of New York at Buffalo, USA. His current research interests include electronic commerce, internet/database marketing, knowledge management, data mining, and decision support systems. Jau-Ji Shen received his Ph.D. degree in Information Engineering and Computer Science from National Taiwan University at Taipei, Taiwan in 1988. From 1988 to 1994, he was the leader of the software group in Institute of Aeronautic, Chung-Sung Institute of Science and Technology. He is currently an associate professor of information management department in the National Chung Hsing University at Taichung. His research areas focus on the digital multimedia, database and information security. His current research areas focus on data engineering, database techniques and information security. Wei-Tse Wang received the B.A. (2001) and M.B.A (2003) degrees in Information Management at Chaoyang University of Technology, Taiwan, R.O.C. His research interests include data mining, XML, and database compression.     

A robust associative watermarking technique based on similarity diagrams

In this paper, a new digital watermarking technique is proposed for watermarking in a random sequence form. By the term associative watermarking we refer to this new technique that combines the traditional idea of digital watermarking with the concept of association rules widely applied in the field of data mining. As our experimental results, after the similarity diagram test, the new digital watermarking technique proves to be capable of guaranteeing the existence and uniqueness of the extracted watermark even when the embedded image has gone through various kinds of image processing procedures.