• Journal of Information Technology Services
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• v.21 no.5
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• pp.51-64
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• 2022

Companies are planning and executing IT projects using information technology as a means to secure external competitiveness. However, IT projects have high risks and uncertainties due to the invisibility of outputs (systems, services, products), and changes in plans frequently occur during project execution. As a result, most IT projects are closed without achieving the target performance. This can lead to a waste of resources and money for the company, which in turn leads to the loss of opportunities to enter new markets. This study intends to analyze the effect of changes in the project plan on customer satisfaction, which is the project performance. Also, we want to find the importance of project planning so that the target performance of the IT project can be achieved. For the empirical analysis of this study, about 500 actual project data were collected. As for the analysis method, statistical analysis such as simple and multiple regression analysis and control effect was performed. Looking at the results of the analysis, it was found that the scope change affects the cost change and the schedule change. Also, changes in scope and cost were found to affect project performance. The theoretical performance of this study proved the theoretical fact that good project performance comes out if the IT project is executed as planned. The practical performance suggested the need for a change in project management by proving that thorough execution of the project planning stage can improve the project performance in the Korean project management culture, where the project planning stage is poorly performed for the rapid implementation of the IT project.

• Korean Journal of Radiology
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• v.23 no.1
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• pp.52-59
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• 2022

Objective: To investigate whether the diagnostic performance of CT angiography (CTA) could be improved by modifying the conventional criterion (anastomosis site abnormality) to diagnose hepatic artery occlusion (HAO) after liver transplantation (LT) in suspected patients with Doppler ultrasound (US) abnormalities. Materials and Methods: One hundred thirty-four adult LT recipients (88 males and 46 females; mean age, 52.7 years) with suspected HAO on Doppler US (40 HAO and 94 non-HAO according to the reference standards) were included. We evaluated 1) abnormalities in the HA anastomosis, categorized as a cutoff, ≥ 50% stenosis at the anastomotic site, or diffuse stenosis at both graft and recipient sides around the anastomosis, and 2) abnormalities in the distal run-off, including invisibility or irregular, faint, and discontinuous enhancement. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the conventional (considering anastomosis site abnormalities alone) and modified CTA criteria (abnormalities in both the anastomosis site and distal run-off) for the diagnosis of HAO were calculated and compared using the McNemar test. Results: By using the conventional criterion to diagnose HAO, the sensitivity, specificity, PPV, NPV, and accuracy were 100% (40/40), 74.5% (70/94), 62.5% (40/64), 100% (70/70), and 82.1% (110/134), respectively. The modified criterion for diagnosing HAO showed significantly increased specificity (93.6%, 88/94) and accuracy (93.3%, 125/134) compared to that with the conventional criterion (p = 0.001 and 0.002, respectively), although the sensitivity (92.5%, 37/40) decreased slightly without statistical significance (p = 0.250). Conclusion: The modified criterion considering abnormalities in both the anastomosis site and distal run-off improved the diagnostic performance of CTA for HAO in suspected patients with Doppler US abnormalities, particularly by increasing the specificity.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.9 no.3
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• pp.39-52
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• 1999

In this paper we propose a new watermarking technique for copyright protection of images. The proposed technique is based on a spatial masking method with a spatial scale parameter. In general it becomes more robust against various attacks but with some degradations on the image quality as the amplitude of the watermark increases. On the other hand it becomes perceptually more invisible but more vulnerable to various attacks as the amplitude of the watermark decreases. Thus it is quite complex to decide the compromise between the robustness of watermark and its visibility. We note that watermarking using the spread spectrum is not robust enought. That is there may be some areas in the image that are tolerable to strong watermark signals. However large smooth areas may not be strong enough. Thus in order to enhance the invisibility of watermarked image for those areas the spatial masking characteristics of the HVS(Human Visual System) should be exploited. That is for texture regions the magnitude of the watermark can be large whereas for those smooth regions the magnitude of the watermark can be small. As a result the proposed watermarking algorithm is intend to satisfy both the robustness of watermark and the quality of the image. The experimental results show that the proposed algorithm is robust to image deformations(such as compression adding noise image scaling clipping and collusion attack).

• Journal of Korea Multimedia Society
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• v.10 no.11
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• pp.1427-1438
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• 2007

Video watermarking technologies are classified into types of four kinds. The first type is to embed the watermark into a raw video signal and to code the watermarked video signal. Most of video watermarking technologies fall into the category of this type. The second type is to apply watermarking to the coding process, such as block DCT and quantization. The third is to directly embed the watermark into the compressed bitstream itself. Generally, it is referred as labelling rather than watermarking. Finally, the fourth is to embed the water mark into MPEG motion vector. This type has the difficulty in real-time process because of the high complexity and has the blocking effects because of DCT-based on coder. In this paper, we proposed the digital video watermarking that embed the watermark in SPIHT video code for I-frame using motion vector analysis. This method can remove the blocking effect occurred at the DCT-based on coder and obtain video data that has progressive transmission property. The proposed method is to select the region for the watermark embedding in I frame using motion vector estimated from the previous P or B frame. And then, it is to perform DWT and embed the watermark based on HVS into the wavelet coefficients in the same subband of DWT as the motion vector direction. Finally, the watermarked video bitstream is obtained by the SPIHT coder. The experimental results verified that the proposed method has the invisibility from the objective and subjective image quality and the robustness against the various SPIHT compression and MPEG re-code.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.37 no.1
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• pp.1-10
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• 2000

In this paper, a new digital watermarking algorithm using wavelet transform is proposed. Wavelet transform is widely used for image processing, because of its multiresolution characteristic which conforms to the principles of the human visual system(HVS). It is also very efficient for localizing images in the spatial and frequency domain. Since wavelet coefficients can be characterized by the gaussian distribution, the proposed algorithm uses a gaussian distributed random vector as the watermark in order to achieve invisibility and robustness. After the original image is transformed using DWT(Discrete Wavelet Transform), the coefficients of all subbands including LL subband are utilized to equally embed the watermark to the whole image. To select perceptually significant coefficients for each subband, we use level-adaptive thresholding. The watermark is embedded to the selected coeffocoents, using different scale factors according to the wavelet characteristics. In the process of watermark detection, the similarity between the original watermark and the extracted watermark is calculated by using vector projection method. We analyze the performance of the proposed algorithm, compared with other transform-domain watermarking methods. The experimental results tested on various images show that the proposed watermark is less visible to human eyes and more robust to image compressions, image processings, geometric transformations and various noises, than the existing methods.

• Journal of Broadcast Engineering
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• v.19 no.3
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• pp.342-354
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• 2014

This paper deals with digital watermarking methods to protect ownership of image with targeting the ultra-high multi-view or free-view image service in which an arbitrary viewpoint image should be rendered at the user side. The main purpose of it is not to propose a superior method to the previous methods but to show how difficult to construct a watermarking scheme to overcome the viewpoint translation attack. Therefore we target the images with various attacks including viewpoint translation. This paper first shows how high the error rate of the extracted watermark data from viewpoint-translated image by basic schemes of the method using 2DDCT(2D discrete cosine transform) and the one using 2DDWT(2D discrete wavelet transform), which are for 2D image. Because the difficulty in watermarking for the viewpoint-translated image comes from the fact that we don't know the translated viewpoint, we propose a scheme to find the translated viewpoint, which uses the image and the corresponding depth information at the original viewpoint. This method is used to construct the two non-blind watermarking methods to be proposed. They are used to show that recovery of the viewpoint affect a great deal of the error rate of the extracted watermark. Also by comparing the performances of the proposed methods and the previous ones, we show that the proposed ones are better in invisibility and robustness, even if they are non-blind.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.39 no.2
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• pp.45-53
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• 2002

A wavelet-based digital watermarking algorithm is proposed that uses the successive subband quantization and human visual system (HVS). After an original image is decomposed into 4-level by the discrete wavelet transform, perceptually significant coefficients (PSC) of each subband excluding the lowest level subband are utilized to embed the watermark. PSC of the baseband ate chosen according to their amplitude and they are slightly modified to embed the watermark by a conventional embedding method. By the successive subband quantization, PSC of the high frequency subband are chosen and slightly modified according to the HVS. We tested the performance of the proposed algorithm compared with the conventional watermarking algorithm by computer simulation. Experimental results show that the proposed watermarking algorithm produces a better invisibility and robustness than the conventional algorithm.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.87-95
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• 2013

"Gone with the wind"(1939, Directed by Victor Fleming) was produced in the stylistic conventions of the classical hollywood cinema, and thus the musical employment also followed the norms of the style, such as late Romantic musical style, serving the narrative, signifier of emotion, and giving continuity and unity. But, at the same time, the statement of the classical theory that the music hides and tailors itself to support the drama - invisibility, inaudibility, narrative cuing and so on - does not seem to explain the musical employment of "Gone with the wind." On the contrary, it hires music to put itself forward, and often times it stops the narrative to show musical spectacles for which the image is tailored to fit the music. These are more of music theatre or music drama features rather than the conventional underscore of the films in that period. In this study analysed the musical employment of "Gone with the wind" to see how it took full advantage of music to lead the narrative in a more active way and to make musical spectacles, by borrowing the technique and style of music theatre, such as, overture and entr'acte, similarities with film musicals, Wagnerism influence, and the use of songs.

• Cross-Cultural Studies
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• v.44
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• pp.7-28
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• 2016

This study examines the sociocultural background of negritude by delving into Caseríos, Reggaeton, and $Trigue{\tilde{n}}os$, which are interrelated with the racism deeply embedded in Puerto Rican society. These terms have also been discussed in relation to the ideological discourse of racial democracy, which has caused Puerto Rican people to be blind to silenced inequality and hegemonic racial policies. Caseríos, housing projects for the poor urban class, are targeted by the state - sponsored project 'Mano Dura'. Due to the policing, control and surveillance of this anticrime project, Caseríos became perceived even more as residential communities of violence, poverty, and insecurity generally connected to the stigmatization of blackness. Reggaeton emerged as a mega hit genre of transnational Puerto Rican music in the 2000s, which in turn, drew attention to both the afrodiaspora in New York and the urban musical power in the Island. This musical genre serves to highlight the meaningfulness of black heritage in the national cultural identity of Puerto Rico. $Trigue{\tilde{n}}idad$ has recently become a common racial cultural term that embraces a broader racial paradigm of mestizaje. This term can function as an alternative concept of blackness, but it has not yet been transformed into enough cultural politics to resist ongoing racial democracy. The three terms intrinsically address both the uprooted racism and potential methods of challenging it. This paper argues the necessity of stronger and more responsive cultural politics to defy the pervasiveness and invisibility of racial discrimination in Puerto Rico.

• Journal of Broadcast Engineering
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• v.26 no.3
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• pp.296-307
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• 2021

A digital hologram (DH) is an ultra-high value-added video content that includes 3D information in 2D data. Therefore, its intellectual property rights must be protected for its distribution. For this, this paper proposes a watermarking method of DH using a deep neural network. This method is a watermark (WM) invisibility, attack robustness, and blind watermarking method that does not use host information in WM extraction. The proposed network consists of four sub-networks: pre-processing for each of the host and WM, WM embedding watermark, and WM extracting watermark. This network expand the WM data to the host instead of shrinking host data to WM and concatenate it to the host to insert the WM by considering the characteristics of a DH having a strong high frequency component. In addition, in the training of this network, the difference in performance according to the data distribution property of DH is identified, and a method of selecting a training data set with the best performance in all types of DH is presented. The proposed method is tested for various types and strengths of attacks to show its performance. It also shows that this method has high practicality as it operates independently of the resolution of the host DH and WM data.