• Convergence Security Journal
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• v.7 no.1
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• pp.29-34
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• 2007

Recently, the distribution and using of the digital multimedia contents are easy by developing the internet application program and related technology. However, the digital signal is easily duplicated and the duplicates have the same quality compare with original digital signal. To solve this problem, there is the multimedia fingerprint which is studied for the protection of copyright. Fingerprinting scheme is a technique which supports copyright protection to track redistributers of electronic information using cryptographic techniques. Only regular user can know the inserted fingerprint data in fingerprinting schemes differ from a symmetric/asymmetric scheme and the scheme guarantee an anonymous before re-contributed data. In this paper, we present a new scheme which is the detection of colluded multimedia fingerprint by neural network. This proposed scheme is consists of the anti-collusion code generation and the neural network for the error correction.

• Journal of Korea Multimedia Society
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• v.20 no.10
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• pp.1619-1627
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• 2017

Image hashing has been successfully applied for the problems associated with the protection of intellectual property, management of large database and indexation of content. For a reliable hashing system, improving hash matching accuracy is crucial. In order to improve the hash matching performance, we propose an asymmetric hash matching method using the psychovisual threshold, which is the maximum amount of distortion that still allows the human visual system to identity an image. A performance evaluation over sets of image distortions shows that the proposed asymmetric matching method effectively improves the hash matching performance as compared with the conventional Hamming distance.

• Annual Conference of KIPS
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• 2000.10a
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• pp.153-156
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• 2000

인터넷을 비롯한 통신기술의 비약적인 발전과 보급, Mpeg, Jpeg 등의 멀티미디어 데이터 압축기술의 발전으로 인하여 문서, 사진, 동영상, 오디오 데이터 등의 다양한 매체들이 디지털화되어 고속으로 전송이 가능하게 되었다. 이러한 멀티미디어 컨텐츠(Multimedia Contents)에 대해 누구나 쉽게 저장과 접근, 이용 가능하게 됨으로써 저작물에 대한 소유권 문제가 큰 이슈로 부각되었다. 본 논문에서는 이러한 멀티미디어 데이터의 저작권을 보호하기 위한 방법들을 살펴보고 각 기법의 특성을 고찰한다. 또한 각 기법들간의 관계 및 체계를 분류하고 저작권 보호에 효율적인 워터마킹(Watermarking)기법과 스테가노그라피(Steganography) 및 핑거프린팅(Fingerprinting)기법을 비교 분석한다.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10b
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• pp.313-318
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• 2007

위치기반서비스에서 사용자의 정확한 위치가 요구되면서 측위와 추적에 대한 연구가 활발히 진행되고 있다. 측위 방법에는 위성기반 방법[1, 2], 로컬네트워크기반 방법[3-6], 센서기반 방법[1, 7, 8, 9]등이 있다. 본 연구에서는 로컬네트워크 중 WLAN (Wireless Local Area Network) 환경의 옥내에서 사용자의 위치를 추적하는 기존의 방법의 정확성을 제고하는 방안을 제안한다. 제안하는 방법은 WLAN 환경에서 RSS를 측정하여 K-NN방식으로 현재 위치를 판단한 다음, 칼만필터를 사용하여 사용자의 위치와 이동경로를 예측한다는 점에서 기존의 방법과 비슷하다. 제안하는 방법의 특징은 도면 정보를 이용하는 것이다. 제안하는 방법은 도면정보로부터 갈림길 영역을 파악하고, 갈림길 영역에서는 측정치에 가중치를 두고 갈림길이 아닌 지역에서는 시스템 모델에 가중치를 두도록 파라메타의 값을 조절한다. 제안하는 방법의 효율성을 실험적으로 증명하기 위한 실험 결과와 분석 내용도 제시한다.

• Journal of Advanced Navigation Technology
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• v.12 no.2
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• pp.180-190
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• 2008

There have been researches into digital Watermarking technology or Fingerprinting vigorously to safeguard Protective rights for knowledge and poverty for digital contents. DRM(Digital Rights Management) is not only Protective rights for knowledge and poverty, but also management and systems that are necessary to put out, circulate and use for contents. This paper proposes two kinds of ideas. One is protecting contents from illegal acts such as illegal copies when the contents are in the process of circulation. The other is the protocol that can give users convenience. Hidden Agents are used so that contents are protected from illegal copies and illegal use in the contents and cuts off those illegal acts. The Agent will be installed without any special setup. In addition, it can replace roles of Watermarking as a protection. Therefore, this paper shows the solution of illegal copies that happens frequently.

• Journal of Korea Multimedia Society
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• v.14 no.3
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• pp.433-439
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• 2011

The positioning system based on wireless AP collects AP information distributed in the real world, stores it into database, and measures the position objects by comparing with searched AP information. The existing fingerprinting method is a probabilistic modeling method that acquires much of the data collected from one location upon database composition, and stores the average of the data for the sake of use it in positioning objects. Using the average value, however, may cause the probability of errors Such errors are fatal weaknesses for services based on the accurate position. This paper described the characteristics and problems of the previously used wireless AP positioning system, and proposed a method of using the AP DB and an MSS mechanism for outdoor positioning in order to solve the aforementioned problems. And the results obtained from experimental tests showed that the proposed method achieved very low error rate(27%) compared with the existing method.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.142-146
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• 2007

Digital Rights Management (DRM) technology has been widely used for protecting the digital contents over the recent years. But the digital contents protected by DRM are vulnerable to various video memory capture programs when DRM packaged contents are decrypted on the consumers' multimedia devices. To make up for this kind of DRM security holes the Forensic Marking (FM) technology is being deployed into the content protection area. Most leading DRM companies as well as big electronics companies like Thomson and Philips already have commercial FM solutions. Forensic Marking technology uses the digital watermarking to insert the user information such as user id, content playing time and etc. into the decrypted and decoded content at the playback time on the consumer devices. When the content containing watermarked user information (Forensic Mark) is illegally captured and distributed over the Internet, the FM detection system takes out the inserted FM from the illegal contents and informs contents service providers of the illegal hacker's information. In this paper the requirements and test conditions are discussed for the commercial Forensic Marking systems.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.102-106
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• 2008

Forensic Marking is the technology that enables the service providers (SP) to identify the illegal digital contents distributors by first inserting markings (data indicating the user information and playback time) in realtime into the digital contents at time of playback of digital contents, and then later by extracting inserted markings from the contents which are illegally captured from the multimedia device such as IPTV STBs and distributed over the Internet. Digital Rights Management (DRM), which is a very popular content protection technology, has the security hole that can be vulnerable because the encrypted digital contents are transformed into their original plaintext forms after the decrypting process on the STBs. Therefore Forensic Marking (FM) has now become a companion content protection solution to DRM. This article describes a new way of tracking up to 4 illegal content users in FM implementation using the blue-difference chroma component of YCbCr color space. This FM technology has many advantages like fast processing time and easy portability to STB devices compared to that of the traditional watermarking processing in the frequency domain.

• Journal of Korea Multimedia Society
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• v.10 no.11
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• pp.1483-1495
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• 2007

Thanks to IEEE 802.11 technique, accessing Internet through a wireless LAN(Local Area Network) is possible in the most of the places including university campuses, shopping malls, offices, hospitals, stations, and so on. Most of the APs(access points) for wireless LAN are supporting 2.4 GHz band 802.11b and 802.11g protocols. This paper is introducing a C# library function which can be used to read RSSIs(Received Signal Strength Indicator) from APs. An LBS(Location Based Service) estimates the current location of the user and provides useful user's location-based services such as navigation, points of interest, and so on. Therefore, indoor, LBS is very desirable. However, an indoor LBS cannot be realized unless indoor position ing is possible. For indoor positioning, techniques of using infrared, ultrasound, signal strength of UDP packet have been proposed. One of the disadvantages of these techniques is that they require special equipments dedicated for positioning. On the other hand, wireless LAN-based indoor positioning does not require any special equipments and more economical. A wireless LAN-based positioning cannot be realized without reading RSSIs from APs. Therefore, our C# library function will be widely used in the field of indoor positioning. In addition to providing a C# library function of reading RSSI, this paper introduces implementation of indoor positioning modules making use of the library function. The methods used in the implementation are K-NN(K Nearest Neighbors), Bayesian and trilateration. K-NN and Bayesian are kind of fingerprinting method. A fingerprint method consists of off-line phase and realtime phase. The process time of realtime phase must be fast. This paper proposes a decision tree method in order to improve the process time of realtime phase. Experimental results of comparing performances of these methods are also discussed.