Hwan Il Kang

A vector watermarking using the generalized square mask

Presents an algorithm for watermark insertion and extraction in a vector image. Most parts of the vector image consist of an array of coordinate values. First, the image is partitioned into blocks with the same area, and every vertex coordinate value within a block is changed to a new coordinate value whose origin is at the south-west vertex of the mask belonging to the associated block. The insertion area is different according to the value of the watermark. Unlike the work of M. Sakamoto et al. (2000), we are able to use an arbitrary size for the square mask. The mask of Sukamoto et al.s work is restrictive since the length of the mask is 2/sup R/-1, where R=1, 2, ..., n. We also show that our method is superior to the previous work against noise attacks.

Path Planning Algorithm Using the Particle Swarm Optimization and the Improved Dijkstra Algorithm

In this paper, we develop the path planning algorithm using the improved Dijkstra algorithm and the particle swarm optimization. To get the optimal path, at first we construct the MAKLINK on the world environment and then make a graph associated with the MAKLINK. From the graph, we obtain the Dijkstra path between the starting point and the destination point. From the optimal path, we search the improved Dijkstra path using the graph. Finally, applying the particle swarm optimization to the improved Dijkstra path, we obtain the optimal path for the mobile robot. It turns out that the proposed method has better performance than the result.

Hybrid Simplex-Harmony search method for optimization problems

This paper proposes the hybrid simplex algorithm (SA)-harmony search(HS) Method. HS method is, the evolutionary algorithm, conceptualized using the musical process of searching for optimization problems. SA helps HS find optimization solution more accurately and quickly. In this paper, the performances of proposed algorithm are compared with the original HS method and other algorithms through unconstrained functions and constrained functions.

Digital Geographical Map Watermarking Using Polyline Interpolation

This paper presents the watermarking algorithm for copyright protection of the digital geographical map composed of vector format. Most of previously related works had a weak point that degrades the accuracy as the quality of the digital geographical map or is easily destroyed by attacks. The proposed watermarking algorithm preserves the accuracy of vertex and is robust enough against attacks, and also it performs the blind watermarking by extracting the watermark without an original map. Finally, through experiments, this paper shows the proposed method is robust enough against attacks such as the elimination and modification of vertices.

A Fuzzy Time Series Prediction Method Using the Evolutionary Algorithm

This paper proposes a time series prediction method for the nonlinear system using the fuzzy system and the genetic algorithm. At first, we obtain the optimal fuzzy membership function using the genetic algorithm. With the optimal fuzzy rules and the input differences, a better time prediction series system may be obtained. In addition, we may obtain the optimal fuzzy membership functions in terms of the evolutionary strategy and we obtain the time series prediction methods using the optimal fuzzy rules. We compare the time series prediction method using the genetic algorithm with that using the evolutionary strategy.

A Digital Audio Watermarking Using Two Masking Effects

In this paper, a new digital audio watermarking algorithm is presented. The proposed algorithm embeds watermark by eliminating some frequency information of audio signal based on human auditory system (HAS). This algorithm is a blind audio watermarking method, which does not require any prior information during watermark extraction process. In this paper, two masking effects are used for audio watermarking, frequency-domain masking effect and time-domain masking effect. This algorithm finds watermarking position using time-domain masking effect and embeds/detects the watermark using frequency-domain masking effect. Detection of embedded watermark is obtained by finding the eliminated frequency using band-pass filter. By using the two masking effects, the degradation of the audio quality can be minimized. It is confirmed that the proposed algorithm has robustness against various attacks such as cropping, down sampling, time stretch, MPEG1-layer3, and MPEG2-AAC compression with good audio quality.

Blind Watermarking Algorithm Using Complex Block Selection Method

Digital watermarking is the technique, which embeds an invisible signal including owner identification and copy control information into multimedia data such as audio, video, images for copyright protection. A new watermark embedding algorithm is introduced in this paper. In this algorithm, complex 8×8 DCT blocks are selected by calculating the AC coefficients of the DCT blocks, and watermark information is embedded into the selected complex blocks using quantization and modulus calculation. This algorithm uses a blind watermark retrieval technique, which detects the embedded watermark without using the original image. The experimental results show that the proposed watermark technique is robust to JPEG compression with 90% of compression ratio and has an excellent PSNR. With the fast watermark extraction property, this algorithm is suitable for real-time watermark extraction applications such as compressed video watermark.

A normalization based image affine estimation technique for computer vision

In this paper, we propose the estimation method for the image affine information for computer vision. The first estimation method is given based on the XYS image normalization and the second estimation method is based on the XSR image normalization. In addition, we show that rotation and aspect ratio information can be obtained using the central moments of both the original image and the sensed image. Finally, we propose the modified version of the normalization method so that we may control the size of the image. It turns out that the XYS method has much better performance than the XSR method for the image having the aspect ratio change

Modelling of biochemical systems using the particle swarm optimization and chaotic theory

In this work, the Particle Swarm Optimization (PSO) algorithm combined with chaotic theory was employed to modeling data of biochemical systems. For this purpose, three case studies will be applied with PSO as parameter estimation problems and examine the performance of the new developed methodology.

Robust stabilization of commensurate fractional order interval plants with PID controllers

In this paper, we study robust stabilization of commensurate fractional order interval polynomial with the PID controller. In this paper, we show that a special class of commensurate fractional order interval plants can be stabilized by PID compensator if some of edge characteristic polynomials can be stabilized by the PID compensator. The proof is based on the fact that the special commensurate fractional order polytope of polynomial is robustly stable if and only if a small set of edge polynomials are robustly stable.