• Journal of KIISE:Information Networking
• /
• v.37 no.2
• /
• pp.150-156
• /
• 2010

Audio watermarking is the process of embedding inaudible information in an audio signal and has been widely used for copyright protection. In this research, we use the audio watermarking not for copyright protection but for the transmission of side information for user convenience, presenting an algorithm suitable for this purpose. Our new algorithm includes watermark embedding/extraction methods during acoustic transmission through the air that employ energy modulation of the audio signal and an efficient two-step synchronization method. The proposed algorithm is evaluated in experiments of conveying information from audio speakers to a mobile phone. The results show that reliable transmission is possible within a 5m range, which is an improvement achieved by our algorithm as compared to the existing one.

• The Journal of the Acoustical Society of Korea
• /
• v.22 no.5
• /
• pp.367-374
• /
• 2003

In this paper, we propose an audio watermarking method using the attribute of tonal masker. First, the attribute of tonal masker as an audio watermarking attribute is analyzed. According to existing researches, it is possible to be imperceptible modulation for the energies of the frequencies that compose a tonal masker. And when the relation between the tone energy and the left or right frequency energy after various signal processing is compared with the one before the processing, very few changes are showed. We propose an audio watermarking method using these attributes of tonal masker. A watermark bit is embedded by the modulation of the difference between the two neighboring frequency energies of a tone. In the detection, the modulated the tonal masker is searched using the key wed in the embedding without original audio and the embedded watermark bit is detected. After each attack of noise insertion, band-pass filtering, re-sampling, compression, echo transform and equalization, the detection error ratios of the proposed method were average 0.11%, 1.26% for Classics and Pops. And the SDG(Subjective Diff-Grades) scale evaluation of the sound quality of the watermarked audio result in the average SDG -0.31.

• The Journal of the Acoustical Society of Korea
• /
• v.28 no.7
• /
• pp.653-660
• /
• 2009

This paper proposes a robust audio watermarking algorithm for copyright protection and improvement of sound quality after embedding a watermark into an original sound. The proposed method computes the FFT (fast Fourier transform) of the original sound signal and divides the spectrum into a subbands. Then, it is necessary to calculate the energy of each subband and sort n subbands in descending order corresponding to its power. After calculating the energy we choose k subbands in sorted order and find p peaks in each selected subbands, and then embed a length m watermark around the p peaks. When the listeners hear the watermarked sound, they do not recognize any distortions. Furthermore, the proposed method is robust as much as Cox's method to MP3 compression, cropping, FFT echo attacks. In addition to this, the experimental results show that the proposed method is generally 10 dB higher than Cox's method in SNR (signal-to-noise ratio) aspect.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.36S no.12
• /
• pp.27-33
• /
• 1999

A wavelet based multiresolution watermarking method using the human visual system (HVS) is proposed, in which a different number of watermarks, in proportion to the energy contained in each band, are embedded into each band. Experiments with various test images show that the proposed three-level wavelet based method is robust to various attacks such as joint photographic experts group (JPEG) compression, smoothing, cropping, collusion, multiple watermarking, and so on.

• Proceedings of the Acoustical Society of Korea Conference
• /
• spring
• /
• pp.331-334
• /
• 2002

의사잡음 시퀀스를 이용한 대역확산 기반의 오디오 워터마킹은 들리지 않으면서도 강인한 워터마크를 만들기 위해 심리음향모델이나 고정필터를 사용하여 의사잡음 시퀀스를 변형시킨다. 그런데, 이러한 방법을 이용하여 스펙트럼 변형된 의사잡음은 고주파 영역에 대부분의 에너지를 갖게 되므로 인위적으로 오디오 신호의 고주파 영역을 잘라내는 공격에 취약하다는 단점이 있다. 본 논문에서는 이러한 단점을 보안하고 강인성 및 잡음의 최소화를 위하여 중간값의 성질을 이용하여 의사잡음을 변형 후 삽입하는 워터마킹 시스템을 제안한다. 중간값 성질을 이용하여 변형한 의사잡음은 원 오디오 신호와의 상관성이 높으며 전주파수 대역에 고르게 분포하는 성질이 있으므로 고주파 영역의 공격에 강인하다. 제안 방법은 의사잡음의 고유성질을 최대로 살린 방법으로 각종 오디오 부호화, 부가잡음, 다운/업 샘플링, 채널변경, 진폭 공격과 같은 다양한 공격에도 워터마크 신호의 검출이 가능하다.

• The Monthly Technology and Standards
• /
• s.59
• /
• pp.28-33
• /
• 2006

• The Magazine for Energy Service Companies
• /
• s.27
• /
• pp.16-19
• /
• 2004

합성고무를 주로 생산하는 금호석유화학 울산공장은 대표적인 에너지과다소비사업장이지만 각종 공정개선을 통한 에너지절감이 상당히 이루어지고 있다. 특히 정부자금을 활용하여 자금부담이 덜하고 신뢰할 수 있는 ESCO사업을 적극 활용, 쿨링워터시스템 개선사업을 비롯해 폐가스 보일러, 폐열회수시스템, 고효율조명 등 다양한 아이템으로 사업을 추진했다. 또한 이 공장은 그룹 차원에서 진행되는 에너지절감활동이 다채롭다.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.13 no.6
• /
• pp.33-43
• /
• 2003

In this paper, we proposed a real-time watermarking algorithm to be combined and to work with a DWT(Discrete Wavelet Transform)-based image compressor. To reduce the amount of computation in selecting the watermarking positions, the proposed algorithm uses a pre-established look-up table for critical values, which was established statistically by computing the correlation according to the energy values of the corresponding wavelet coefficients. That is, watermark is embedded into the coefficients whose values are greater than the critical value in the look-up table which is searched on the basis of the energy values of the corresponding level-1 subband coefficients. Therefore, the proposed algorithm can operate in a real-time because the watermarking process operates in parallel with the compression procession without affecting the operation of the image compression. Also it improved the property of losing the watermark and the efficiency of image compression by watermark inserting, which results from the quantization and Huffman-Coding during the image compression. Visual recognizable patterns such as binary image were used as a watermark The experimental results showed that the proposed algorithm satisfied the properties of robustness and imperceptibility that are the major conditions of watermarking.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.12C
• /
• pp.1214-1221
• /
• 2005

In this paper, we propose a digital watermarking method for still images, in which the human visual system (HVS) is used in the discrete cosine transform (DCT) domain. The modulation transfer function (MTF) of the HVS model is employed to increase the invisibility of the inserted watermark in images. The proposed watermarking method is shown to be robust to several common image processing techniques, including lowpass filtering and cropping. Also, using the energy relationship of the DCT, we derive the equation that directly computes the watermark weighting factor in the DCT domain for the specified peak signal to noise ratio (PSNR) of the still image and the length of watermark to be inserted. The difference between desired PSNR and PSNR in spatial domain is within 0.07dB for the 7 test images.

• Electronics and Telecommunications Trends
• /
• v.29 no.2
• /
• pp.87-96
• /
• 2014

세계 인구증가 및 지속적 발전에 따라 에너지 사용이 폭발적으로 증가하고 이를 원인으로 온실가스 배출, 기후변화, 물 부족 스트레스로 이어지는 악순환이 점차 심화될 것으로 전망됨에 따라 이에 대한 대응에 관심이 높아지고 있는 현실이다. 이와 같은 물 문제에 대한 주요 대응 방안 중 하나가 ICT(Information and Communication Technology)에 기반한 효율적 수자원 관리 기술인 스마트 워터 그리드라 할 수 있다. 본 논문에서는 스마트 워터 그리드와 기존의 스마트 파워 그리드를 비교하고, 스마트 워터 그리드의 주요 기술요소들에 대한 기술개발 동향과 표준화 동향을 살펴본다.