Taek Yong Nam

An Objectionable Image Detection System Based on Region of Interest

In this paper, we propose the objectionable image detection system based on ROI. The proposed system excels in that ROI detection method is specialized in objectionable image detection. In addition, we propose the novel feature consisting of weighted SCD based on ROI and skin color structure descriptor for classifying objectionable image. Using the ROI detection method, we can reduce the noisy information in image and extract more accurate features for classifying objectionable image. We can also increase the performance of classification system using the skin color information which is the most representative characteristic of objectionable image. An objectionable image is classified as follows. First, the proposed system extracts the ROI from an input image, and then generates the feature using the color information of ROI image and the skin color structure information. The generated feature is used as an input to the SVMs which determines whether an image is objectionable or not. Experimental results show that the proposed ROI detection method can detect ROI exactly. Additionally, the proposed system can achieve the better performance than existing system.

Detecting adult images using seven MPEG-7 visual descriptors

In this paper we introduce an effective method of the adult image classification via MPEG-7 descriptors. The proposed system uses MPEG-7 descriptors as the main feature of the adult image classification systems. The simulation shows that the proposed image classification system performs the 5 class classification task with success rate of above 70%.

FPGA based intrusion detection system against unknown and known attacks

Network intrusion detection systems often rely on matching patterns that are gleaned from known attacks. While this method is reliable and rarely produces false alarms, it has the obvious disadvantage that it cannot detect novel attacks. Accordingly, an alternative approach which can be a combination with pattern matching approach is needed. We have made effort to design and implement high speed protocol anomaly and signature based intrusion detection approach to detect known and unknown attacks. This approach extracts a set of service fields from the application payload where many attacks occur and analyzes the value of fields to verify attack. This approach is implemented on the FPGA (Xilinx Virtex II pro) device to process packet at gigabit-per-second data rates.

The method of P2P traffic detecting for P2P harmful contents prevention

Conventionally, a main interest in a computer security has been focused on protection of a computer system itself, i.e., protection against viruses or system attacks such as denial of service attacks (DoS attack), or communication encryption used for cash transfer service at a bank. However, with regard to influence given by exchanging contents to human beings, a research on automatic detection and blocking of obviously harmful information is now required. Some large companies have already constructed a monitoring system in their own intranet to prepare outflow of essential company secrets. The construction of monitoring and protection system may lead to invasion of private information so that there may occur an extremely subtle legal problem. Therefore, a method of developing a system detecting and preventing obviously harmful information or illegal information is required. In this paper, we design the method of monitoring and preventing P2P traffic. It is a part of harmful contents preventing in the peer to peer network

A Hierarchical Text Rating System for Objectionable Documents

In this paper, we classified the objectionable texts into four rates according to their harm- fulness and proposed the hierarchical text rating system for objectionable documents. Since the documents in the same category have similarities in used words, expressions and structure of the document, the text rating system, which uses a single classification model, has low accuracy. To solve this problem, we separate objectionable documents into several subsets by using their properties, and then classify the subsets hierarchically. The proposed system consists of three layers. In each layer, we select features using the chi-square statistics, and then the weight of the features, which is calculated by using the TF-IDF weighting scheme, is used as an input of the non-linear SVM classifier. By means of a hierarchical scheme using the different features and the different number of features in each layer, we can characterize the objectionability of documents more effectively and expect to improve the performance of the rating system. We compared the performance of the proposed system and performance of several text rating systems and experimental results show that the proposed system can archive an excellent classification performance.

Secure rejoining scheme for dynamic sensor networks

The establishment of cryptography keys is one of the challenging problems in the sensor networks. Key Infection [1] is a promising model to solve this problem on the commodity sensor networks without complex mechanism. This model, however, does not consider the mobility of sensors, so if sensor nodes move out of initial communication range, then they cannot rejoin the network. So, key infection model has been limited to the static sensor network. To be applied on the dynamic sensor network, therefore, key infection model has to be extended to handle nodes rejoining. In this paper, we propose secure rejoining scheme for dynamic sensor networks and verify the proposed scheme formally. Our scheme is secure, since it uses old pair-wise key information to verify sensor nodes rejoining. Furthermore, our scheme does not require additional verification information and maintains the reasonable number of links.

Secure key management scheme for SDH-based all-optical networks

We propose the new secure key management scheme for SDH-based WDM AON. The problem that is to have no overhead data for security service on SDH format may be overcome easily by using the proposed key management scheme. The major advantages of the proposed architecture are that the end-to-end security service can be offered and the key management of a cryptosystem can be implemented easily. The proposed secure SDH-based WDM AON architecture have the property of tapping resistance : the key management channel can monitor any tapping attack using the cutoff wavelength of the fiber ; the encryption function of the optical cryptosystems can prevent eavesdroppers from understanding information by tapping. In addition, the proposed architecture can ensure that synchronization of key stream sequence between the optical cryptosystems is maintained perfectly and security management for APS can be performed easily. The proposed architecture can be applicable to the secure node system.

Interactive multimedia service system on ATM networks

This paper presents an interactive multimedia conferencing system designed in compliance with the telecommunication information networking architecture software concepts and principles. The interactive multimedia conference service is implemented on Ionas Orbix as a distributed processing environment, windows-NT PC, UNIX Workstations, interconnected by ATM networks. The multimedia conference systems is developed to provide the network based multimedia conferencing services for large public ATM networks.