• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.9
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• pp.663-669
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• 2004

The mobile tole-cardiology system is the new research area that support an ubiquitous health care based on mobile telecommunication networks. Although there are many researches presenting the modeling concepts of a GSM-based mobile telemedical system, practical application needs to be considered both compression performance and error corruption in the mobile environment. This paper evaluates three wavelet ECG compression algorithms over CDMA networks. The three selected methods are Rajoub using EPE thresholding, Embedded Zerotree Wavelet(EZW) and Wavelet transform Higher Order Statistics Coding(WHOSC) with linear prediction. All methodologies protected more significant information using Forward Error Correction coding and measured not only compression performance in noise-free but also error robustness and delay profile in CDMA environment. In addition, from the field test we analyzed the PRD for movement speed and the features of CDMA 1X. The test results show that Rajoub has low robustness over high error attack and EZW contributes to more efficient exploitation in variable bandwidth and high error. WHOSC has high robustness in overall BER but loses performance about particular abnormal ECG.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.9C
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• pp.1289-1297
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• 2004

Digital watermarking is a technique which blends intellectual property right with security Blind watermarking 1S one of the difficult watermark technique because original data or inserted watermark is not needed. In this paper, we propose a new blind watermarking method using energy quantization in wavelet domain to insert watermark. The proposed method is robust for various attacks and attack strength because watermark strength is adaptively changed for energy variation of attacks. Simulation results show the proposed method is robust to various attacks such as noise addition, cropping, blurring, sharpening, maintaining imprescriptibility.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.4
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• pp.85-95
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• 1998

In this paper, a new watermarking method for a copy protectionof images is proposed. The proposed method adaptively embeds a watermark in the frequency domain of images using human visual system model. For this purpose, the Just Noticeable Differences(JNDs) of each frequency coeffeicient value of a luminance plane is first found using Watson and Solomon's visual system model. An invisible maximum watermark value with is different in every position according to the characteristics of images is determined usig JND and Minkowski metric. A low frequency domain is divided into two sets based on a PN-sequence to protect thewatermark from the attack. The watermarks are added to one set of coefficients and detecting a watermark, the difference between the mean values of absolute coefficient values of both sets is calculated. The embedded watermark is tested using statistical hypothesis based on test static dertermined by the ean difference. To demonstrate the perfromance of the proposed method, the new watermarking method is applied to a high frequency image and low frequency images. Experimenatal results show the watermark is invisible and robust to JPEGlossy compression and noise.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.12
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• pp.2330-2335
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• 2008

In this paper, we proposed a robust watermark scheme for image based on the discrete wavelet transform. In the first, we use the triplet method for embedding and extraction of watermark. Triplet method uses relationship among the discrete wavelet coefficients at the same position in the three detail subband of image. In the second, we use barcode Pattern Image for watermark scheme. By using barcode Pattern Images, a user is able to make many kinds of own watermark. In the third, the proposed method for image watermark provides the invisiblility which the other user can not discriminate watermark from watermarked image. The advantage of the proposed method is visibility when we extracted watermark from the image. The corresponding experimental results show that the proposed method has performance of a robustness from the noise attack.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.606-608
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• 1998

Digital watermarking is the technique which embeds the invisible signal into multimedia data such as audio, video, images, for copyright protection, including owner identification and copy control information. In this paper, a new watermark detection algorithm by local masking cross covariance between watermarked signal and pseudo noise signal is proposed. The proposed algorithm enhances the detection probability for embedding information. Since reducing detection errors for the weak embedding signals, the algorithm improves the image quality and robusts against illegal attack to delete the embedding information and data compression applications such as JPEG and MPEGs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.3B
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• pp.557-564
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• 2000

This paper presents a watermarking algorithm for embedding visually recognizable pattern (Mark, Logo, Symbol, stamping or signature) into the image. first, the color image(RGB model)is transformed in YCbCr model and then the Y component is transformed into 3-level wavelet transform. Next, the values are assembled with pattern watermark. PN(pseudo noise) code at spread spectrum communication method and mutilevel watermark weights. This values are inserted into discrete wavelet domain. In our scheme, new calculating method is designed to calculate wavelet transform with integer value in considering the quantization error. and we used the color conversion with fixed-point arithmetic to be easy to make the hardware hereafter. Also, we made the new solution using mutilevel threshold to robust to common signal distortions and malicious attack, and to enhance quality of image in considering the human visual system. the experimental results showed that the proposed watermarking algorithm was superior to other similar water marking algorithm. We showed what it was robust to common signal processing and geometric transform such as brightness. contrast, filtering. scaling. JPEG lossy compression and geometric deformation.

• Journal of Information Processing Systems
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• v.15 no.2
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• pp.271-287
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• 2019

The synchronization scheme based on moving average is robust and suitable for the same rule to be adopted in embedding watermark and synchronization code, but the imperceptibility and search efficiency is seldom reported. The study aims to improve the original scheme for robust audio watermarking. Firstly, the survival of the algorithm from desynchronization attacks is improved. Secondly, the scheme is improved in inaudibility. Objective difference grade (ODG) of the marked audio is significantly changed. Thirdly, the imperceptibility of the scheme is analyzed and the derived result is close to experimental result. Fourthly, the selection of parameters is optimized based on experimental data. Fifthly, the search efficiency of the scheme is compared with those of other synchronization code schemes. The experimental results show that the proposed watermarking scheme allows the high audio quality and is robust to common attacks such as additive white Gaussian noise, requantization, resampling, low-pass filtering, random cropping, MP3 compression, jitter attack, and time scale modification. Moreover, the algorithm has the high search efficiency and low false alarm rate.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.07a
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• pp.343-345
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• 2020

본 논문에서는 선택적 노이즈 캔슬링을 위한 환경 인지 기술을 제안한다. 기존의 노이즈 캔슬링은 모든 소리를 구분 없이 차단하여 여러 가지 문제를 유발할 수 있으며 공통된 노이즈 캔슬링 동작으로 각 소음에 최적화된 성능을 보장할 수 없다. 이러한 문제를 해결하기 위해 제안하는 방법은 대표적 오디오 특성인 멜-스펙트로그램과 스펙트로그램 기반의 시간적 특성 벡터를 사용하여 환경 인지를 진행한다. 본 논문에서는 attack, rotation, sawing으로 구성된 3가지 소음과 speech, tonal로 구성된 2가지 비 소음으로 총 5가지 클래스를 분류한다. 제안하는 방법에서 특성 벡터로 멜-스펙트로그램만을 사용했을 때 87.5%의 분류 성능을 보였으며, 스펙트로그램 기반의 시간적 특성을 추가했을 때 분류 성능이 91.2%로 향상되었다.

• Spatial Information Research
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• v.21 no.3
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• pp.31-43
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• 2013

Although the vector map data possesses much higher values than other types of multimedia, the data copyright and the protection against illegal duplication are still far away from the attention. This paper proposes a novel watermarking technique which is both robust to diverse attacks and optimized to a vector map structure. Six approaches are proposed for the design of the watermarking algorithm: point-based approach, building a minimum perimeter triangle, watermark embedding in the length ratio, referencing to the pixel position of the watermark image, grouping, and using the one-way function. Our method preserves the characteristics of watermarking such as embedding effectiveness, fidelity, and false positive rate, while maintaining robustness to all types of attack except a noise attack. Furthermore, our method is a blind scheme in which robustness is independent of the map data. Finally, our method provides a solution to the challenging issue of degraded robustness under severe simplification attacks.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.24 no.5
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• pp.1013-1022
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• 2014

Correlation Power Analysis (CPA) is a type of Side-Channel Analysis (SCA) that extracts the secret key using the correlation coefficient both side-channel information leakage by cryptography device and intermediate value of algorithms. Attack performance of the CPA is affected by noise and temporal synchronization of power consumption leaked. In the recent years, various researches about the signal processing have been presented to improve the performance of power analysis. Among these signal processing techniques, compression techniques of the signal based on Principal Component Analysis (PCA) has been presented. Selection of the principal components is an important issue in signal compression based on PCA. Because selection of the principal component will affect the performance of the analysis. In this paper, we present a method of selecting the principal component by using the correlation of the principal components and the power consumption is high and a CPA technique based on the principal component that utilizes the feature that the principal component has different. Also, we prove the performance of our method by carrying out the experiment.